Researchers rely on artificial bone material to stand in for the real thing. Up to now, however, no one has looked at how well the two materials match.

Biomechanical engineers often use biological bone for studies, especially for implants and corrective surgeries. However, biological bone is expensive to source and ship, varies in quality and cost, and can arrive in a degraded or diseased state that is unsuitable for research. 
 
For nearly 40 years, SynboneVR has developed synthetic bones used in biomechanical research as a way to offset some of the cost and risk of using biological bone. Biomechanical engineers continue to rely on these synthetic bones as standards for comparison in their own orthopedic design work. However, there is no prior research that summarizes the mechanical properties of these synthetic bones in order to understand their general performance, or how well they represent biological bone.

Synthetic Bone Versus Reality 

Many people consider themselves to be proficient in applications such as computer assisted design. But true experts operate on a totally different level.&nbsp;

Some people are good at certain things, others not so much. That&rsquo;s as true in mechanical engineering as in any other field that requires specialized skills and knowledge. But what distinguishes an average proficient person from a true expert in, for example, the essential engineering skill of computer-aided design (CAD)? Is it simply a matter of experience, or are other factors such as an individual&rsquo;s particular approach to a certain task involved? How can we speed up the process of turning the merely competent into CAD superstars? 
 
Alison Olechowski, assistant professor in the University of Toronto&rsquo;s Department of Mechanical and Industrial Engineering, decided to find out. Working with graduate students James Chen and Yuanzhe Deng, she designed a study to characterize the differences and similarities in CAD modeling approaches, patterns, and strategies between proficient and expert users. The work was published in the ASME Journal of Mechanical Design.

Many people consider themselves to be proficient in applications such as computer assisted design. But true experts operate on a totally different level.

What Makes a CAD Expert?

Núria Boix Rodríguez, postdoctoral researcher at KU Leuven, says engineering design can prepare industry for Europe&rsquo;s circular economy action plan.

Electronic waste is a growing problem in many parts of the world. One region that has taken steps to rein in waste is the European Union, which has set tough new standards with the intent of creating a so-called circular economy where old products become the building blocks for new ones. To see how this proposal would affect mechanical engineers, Núria Boix Rodríguez and Claudio Favi looked at mechatronic products, which combine mechanical and electronic components. Boix Rodríguez, now a postdoctoral researcher at KU Leuven in Belgium, discusses the role mechanical engineers could play in designing machines that can extend their service lives through repairability.

Design to Disassemble

Forget the skyhook. Researchers have developed a mechanism that can walk over to an object, climb on top, and hold on.

The Creeping Claw

July-September 2024

New research from the University of Salerno provides methods on how to detect and protect connected vehicles from cyberattacks.

<var>What if your car was as vulnerable to hack into as your laptop? The reality is cars today are basically a computer on wheels. According to Car and Driver, 40 percent of a new car&rsquo;s cost is driven by electronic components. The New York Times reported that a modern vehicle could contain more than 3,000 computer chips. Electronics are such an essential part of a car&rsquo;s design that the shortage of semiconductors due to supply chain disruption from the pandemic has impacted auto assembly lines worldwide, creating a lack of new vehicles on the market.</var> 
 
By introducing computer systems into vehicles, hackers have found ways to exploit their vulnerabilities. In 2015, Black Hat security researchers Charlie Miller and Chris Valasek hacked a Jeep Cherokee via its infotainment system. Miller and Valasek exploited how the vehicle autogenerated its Wi-Fi password based on the time when the car&rsquo;s multimedia system would turn on. Through the infotainment system, the hackers could manipulate the air conditioner, the radio, the windshield wipers, and even the transmission. On a road test with Wired magazine, the hackers cut the transmission as the vehicle was driving 70 mph on the highway. This past February, German teenager David Colombo identified a vulnerability in the TeslaMate, a third-party application used by Tesla owners to analyze car performance. By hacking the app, Colombo was able to unlock doors, turn on and off the headlights, and control the radio. He was even able to track in real-time the location of the car.

Advancing Cybersecurity in Connected Vehicles

Explore how adverse weather conditions can impact autonomous vehicles&rsquo; lidar cameras.

<var>Lidar, or light detection and ranging, is a popular remote sensing method used for measuring the exact distance to an object. These imaging systems are increasingly used in the development of autonomous vehicles (AVs). However, final technology implementation cannot yet be achieved because major AV manufacturers are only now starting to select providers for data collection units that can be introduced in commercial vehicles.</var> 
One of the biggest unknowns in the development of AVs is how adverse weather conditions challenge the development of safe and reliable advanced autonomous systems for sensing and perception. How does the diffraction of light through rain, fog, and snow limit lidar performance?

How Self-Driving Cars See in Extreme Weather

Interview with Luca Capriotti

Luca Capriotti, former president of the International Youth Nuclear Congress, shares his passion for nuclear energy and beliefs that it can become a viable, safe power source to be used globally and responsibly in the future.

The Future of Power is Nuclear

Infographic: Sodium-Cooled Fast Reactor

<var>Most nuclear reactors in operation today use water as a coolant, but one promising alternative looks to replace water with liquid sodium. Sodium can be heated to high temperatures before boiling, which means that a sodium-cooled reactor can operate at atmospheric pressure and can use a thinner reactor vessel. These reactors also will produce less radioactive waste. Explore the diagram of a sodium-cooled fast reactor below.</var>

Sodium-Cooled Fast Reactor

July-September 2022

<var>Using 3D scanning, 3D simulation, and CAD, engineers at the Queensland University of Technology have created a patient-specific contoured mattress that successively supports patients in the operating room.</var>
Paige Little is an expert on using state-of-the-art imaging technology to understand ideal body position and support for enhancing the quality of sleep. It&rsquo;s the kind of research used to improve beds for the home. But in 2018, Little was contacted by a consultant who asked for something more serious. Could she design a customized, patient-specific surgical mattress for a 10-year-old about to undergo spinal surgery?

The patient had Morquio syndrome, a disorder that causes skeletal abnormalities and neuromuscular scoliosis. She would need to lie safely on her stomach and the front of her body for the duration of the surgery.

&ldquo;Intraoperative patient position is always a critical factor in spinal surgery, particularly in the case of prone patient positioning, where the anatomy and physiology of the torso is such that additional pressure may have adverse effects on the cardiopulmonary system as well as causing skin and muscle necrosis,&rdquo; Little said. &ldquo;Optimal patient positioning for spine surgery is vital for surgical success and the minimization of complications intra and postoperatively.&rdquo;

Little, an associate professor at the school of mechanical, medical, and process engineering at Queensland University of Technology, is up to the challenge. Using an innovative digital workflow involving 3D surface scanning, 3D simulation and computer-aided design (CAD), she successfully created a customized theater mattress with the patient&rsquo;s specific body-contour requirements. The operation was a success, and the surgical team praised the mattress and its positive impact on patient outcome.
<img alt="" src="~/getmedia/3cd9331a-8fc6-47de-8bf9-c54a38524afa/patient-img1.jpg" /> <var>Dr Paige Little at Research Centre Qld Children&rsquo;s Hospital.</var>

<h5>Patient-specific design</h5>

Little&rsquo;s goal was to create a customized mattress to hold the patient safely and reduce possible skin damage during the surgery procedure. By using digital simulation tools and CAD, she was able to create a patient-specific surgical mattress that fit the contours of the patient&rsquo;s body. This made it easier for the surgeon to relieve load bearing on prominent anatomical features during the surgery because the support surface was tailored to the patient&rsquo;s anatomy for the lengthy procedure.

&ldquo;The design process is based in CAD, and for many of the mattresses I have designed, I use Solidworks to create the mattress contours,&rdquo; Little said. &ldquo;We have recently explored the use of CNC machining to create the surface contours in the polyurethane foam, and with high spindle speeds it is possible to machine this foam using standard tooling. The machining is very successful with well-defined surface contours, and relatively little post-process cleaning is needed to remove dust waste. The foams do not require freezing to machine them. They also do not release toxic fumes or particulate matter.&rdquo;

Topographic scanning of the entire patient was required to create a mattress contour. &ldquo;The contour is not a replica of the patient&rsquo;s anatomy, but rather is custom-designed using the topographic scan as a basis,&rdquo; Little said. &ldquo;The design process cannot be parameterized&mdash;the design is created for each patient using CAD methods to alleviate pressure on the skin surface over areas that are delicate, or regions of the anatomy that cannot bear load for long periods of time. For some corrective surgeries, the patient may be lying stationary for many hours.&rdquo;

Manufacture is currently a manual, just-in-time process. The process may benefit from CNC machining or robotic manufacturing, especially for mattress contours that are for large or tall individuals or have deep cutouts and/or overhangs.

Sealy of Australia then manufactured the final mattress product. Technicians used the 3D model to hand-cut and piece together multiple layers of soft hypo-allergenic foam to conform exactly to the patient&rsquo;s anatomy.

The custom mattress is effectively contoured to the patient&rsquo;s anterior anatomy during surgery. Intraoperative monitoring indicated the patient was not under undue cardiovascular strain over the course of the operation &ldquo;and she successfully remained in the prone position for the entire eight-hour operation,&rdquo; Little said. &ldquo;Immediately postoperatively, there was no evidence of excessive interface pressure between the patient and the support, suggesting the custom-fit mattress successfully distributed the patient&rsquo;s body weight, alleviating regions of excessive pressure.&rdquo;
<img alt="" src="~/getmedia/a3cf9bdb-f951-4224-a7dc-5c8ec7269b24/patient-img2.jpg" /><var>Sealy of Australia R&amp;D manager Daniel Green exams form that contours to the patient&rsquo;s torso.</var>

<h5>Moving Forward</h5>

Since the first use of the surgical mattress, Little has designed 11 other supportive mattresses for pediatric patients with unique anatomies requiring support during surgery&mdash;all with successful results.

The next step is to continue showcasing the mattresses to a broader clinical audience so other patients can benefit from the use of customized body supports during surgery. &ldquo;Their surgical teams will also gain confidence in reducing the risks of complications due to extended periods of weight-bearing in patients with unique conditions,&rdquo; Little said.

The digital workflow she used to design the mattresses can also be applied to the design and advanced manufacturing of other custom-fit devices to assist in treatment and/or rehabilitation of patients. &ldquo;These same techniques&mdash;3D topographic scanning, 3D simulation, and CAD methods&mdash;can be applied to the design of customized corrective/rehabilitation orthoses,&rdquo; Little said, &ldquo;or to the custom design of supports for radiation therapy to ensure the patient is positioned in a repeatable position between treatment appointments.&rdquo;

Using 3D scanning, 3D simulation, and CAD, engineers at the Queensland University of Technology have created a patient-specific contoured mattress that successively supports patients in the operating room.

<var>Using 3D scanning, 3D simulation, and CAD, engineers at the Queensland University of Technology have created a patient-specific contoured mattress that successively supports patients in the operating room.</var>

Paige Little is an expert on using state-of-the-art imaging technology to understand ideal body position and support for enhancing the quality of sleep. It&rsquo;s the kind of research used to improve beds for the home. But in 2018, Little was contacted by a consultant who asked for something more serious. Could she design a customized, patient-specific surgical mattress for a 10-year-old about to undergo spinal surgery?

The patient had Morquio syndrome, a disorder that causes skeletal abnormalities and neuromuscular scoliosis. She would need to lie safely on her stomach and the front of her body for the duration of the surgery.

&ldquo;Intraoperative patient position is always a critical factor in spinal surgery, particularly in the case of prone patient positioning, where the anatomy and physiology of the torso is such that additional pressure may have adverse effects on the cardiopulmonary system as well as causing skin and muscle necrosis,&rdquo; Little said. &ldquo;Optimal patient positioning for spine surgery is vital for surgical success and the minimization of complications intra and postoperatively.&rdquo;
Little, an associate professor at the school of mechanical, medical, and process engineering at Queensland University of Technology, is up to the challenge. Using an innovative digital workflow involving 3D surface scanning, 3D simulation and computer-aided design (CAD), she successfully created a customized theater mattress with the patient&rsquo;s specific body-contour requirements. The operation was a success, and the surgical team praised the mattress and its positive impact on patient outcome.

Patient Support Via Customized Surgical Mattresses

<var>Hydrogen seems like an ideal fuel, but a feasibility analysis reveals the factors that will determine its success.</var>
Hydrogen has the highest energy density by weight of any fuel. So it only makes sense that compressed hydrogen gas is being considered as a carbon-free replacement for diesel in heavy-duty trucks. A hydrogen-fueled truck fleet would substantially reduce greenhouse gas emissions and other pollutants from the freight industry.

Before that can happen, engineers need to work out the optimum technology to make hydrogen economical as well as clean.

​&ldquo;Hydrogen technology is currently expensive because of relatively low deployment. Once it is more common, the refueling infrastructure cost should decrease significantly. Hydrogen refueling infrastructure can be implemented immediately. It has the potential to be very economical,&rdquo; said Wahiba Yaici, a research scientist at the CanmetENERGY Research Centre, Natural Resources Canada in Ottawa, Ontario.

The cost of hydrogen itself looms as the main element in the acceptance of compressed hydrogen. It is rarely found isolated and must go through processes to extract it. Each hydrogen production method involves separating hydrogen from some compound. Common extraction processes include natural gas reforming, biomass gasification, and coal gasification. So-called green hydrogen is produced by using renewable energy such as solar and wind to power the electrolysis of water or other hydrogen-making reactions.
<img alt="A truck cab with visible hydrogen fuel tank" src="~/getmedia/c92a71b0-061d-466a-b7d5-8b3ffeabf1ff/hydrogen-img1.jpg" /><var>Generally, green hydrogen is more expensive than hydrogen produced by other methods, but it also has the advantage of producing zero carbon emissions.</var>

Storing hydrogen is another issue. Hydrogen at a fueling station can be stored either as a gas or a liquid. Storing hydrogen as a gas typically requires high-pressure tanks at 5,000 to 10,000 psi. Storage as a liquid requires cryogenic temperatures, as the boiling point of hydrogen at one atmosphere pressure is &minus;252.8 &deg;C (-423 &deg;F).

The main options for onboard hydrogen storage in vehicles are gaseous storage at 5,000 psi or at 10,000 psi in thermally insulated tanks or in materials with superior chemical properties, like metal hydrides or organic compounds,&rdquo; Yaici said.

To address the hydrogen refueling scenario for big trucks, Yaici teamed with Michela Longo, an associate professor at the Politecnico di Milano in Italy, to write a paper, &ldquo;Hydrogen Gas Refueling Infrastructure for Heavy-Duty Trucks: A Feasibility Analysis,&rdquo; for the ASME Journal of Energy Resources Technology. Both authors are mechanical engineers. The pair chose to pursue hydrogen because it can be used as fuel in modified internal combustion engines (ICEs), reducing the need to purchase new vehicles. Existing diesel engines can easily be modified to burn hydrogen. This is in contrast to the fuel-cell-powered vehicles most people think of when talking hydrogen; fuel cells combine hydrogen and oxygen, yielding water, heat, and electricity used to power an electric motor that drives the vehicle.

This paper investigates the feasibility of developing a nationwide network of hydrogen refueling infrastructure to help convert the long-haul, heavy-duty (LHHD) truck fleet from diesel fuel to hydrogen. Diesel is currently the main fuel used to transport freight over the road.

The team carried out a technical analysis to estimate the number of hydrogen refueling stations needed to convert the fleet of LHHD vehicles to hydrogen. They also did an economic analysis to evaluate the final selling price of hydrogen.

According to Yaici, &ldquo;Results from the techno-economic study showed that hydrogen prices can vary significantly.&rdquo; On average, they found hydrogen to cost 239 percent more than diesel due to the diverse costs of the various production methods for hydrogen. Hydrogen also has about 2.6 times the energy density of diesel fuel by weight, which serves as an equalizer. Energy density by volume is another matter because at the operating temperature of trucks, diesel is a liquid while hydrogen is a gas, giving it a lower energy density by volume if it is not liquefied by cryogenics. Regardless of the hydrogen production method, the process can occur at a central facility or locally where it is needed.

&ldquo;A central system can increase the scope of production by producing hydrogen at large facilities that take advantage of bulk processes to reduce costs per unit,&rdquo; Yaici said. &ldquo;Nevertheless, hydrogen must be transported to its destination via pipeline or trucks. This will increase the operational fees. A distributed process, one where hydrogen is produced on demand locally, eliminates the need to deliver hydrogen over long distances.&rdquo;
<img alt="A hydrogen &quot;gas&quot; pump accompanied by a small array of solar panels" src="~/getmedia/7f96ca95-97e5-4062-9f56-5da4b3d880e5/hydrogen-img2.jpg" />
Hydrogen stations are built to refuel vehicles in similar manner to those used by diesel stations. Each refueling station will consist of a compressor, storage tanks, and at least one dispenser. Yaici pointed out the versatility of the feasibility study. &ldquo;The methodology and models proposed can be used for studying the techno-economics of hydrogen refueling stations in any country and for other types of ICE fleets or fuel cell vehicles,&rdquo; he said.

This includes refueling stations for vehicle fleets powered by renewable fuels such as renewable natural gas or biofuels. Engineering analyses such as this one will help shape the future of transportation.

Hydrogen seems like an ideal fuel, but a feasibility analysis reveals the factors that will determine its success.

<var>Hydrogen seems like an ideal fuel, but a feasibility analysis reveals the factors that will determine its success.</var>
Hydrogen has the highest energy density by weight of any fuel. So it only makes sense that compressed hydrogen gas is being considered as a carbon-free replacement for diesel in heavy-duty trucks. A hydrogen-fueled truck fleet would substantially reduce greenhouse gas emissions and other pollutants from the freight industry.

Before that can happen, engineers need to work out the optimum technology to make hydrogen economical as well as clean.

Putting Hydrogen to the Economic Test

Interview with Moncef Krarti

Moncef Krarti, head of the Building System Program at the University of Colorado, Boulder, discusses ways to turn down the temperature on hot, overcrowded urban areas.

Cooling Cities by Combating Heat Islands

Infographic: Pneumatic Help for Grasping

<div class="infogram-embed" data-id="_/JNK9h2xLuaalwUNVZqrN" data-title="Pneumatically-Powered Help for Grasping" data-type="interactive">&nbsp;</div>
 
&nbsp;

Researchers hope this pneumatic grip glove could soon help relieve industrial workers of some pain.

Workers who must repeat forceful actions with their hands&mdash;whether operating industrial hand tools or typing on a keyboard&mdash;are often subject to carpal tunnel syndrome and other cumulative trauma disorders, which not only are painful but also diminish grip strength. Naveen Chandrashekar, a professor of mechanical and mechatronics engineering at the University of Waterloo in Ontario, and graduate student Daniel Loewen, now chief technology officer at ioAirFlow in Winnipeg, looked for a way to reduce the force needed by workers operating hand tools, which would lean to less wear and tear on the hands and wrists.

Pneumatic Help for Grasping

October-December 2022

Through a complete review of published research over the last 60 years, researchers aim to propel development of new head injury metrics forward.

<var>Through a complete review of published research over the last 60 years, researchers aim to propel development of new head injury metrics forward.</var>

Metrics that help engineers design safer helmets and vehicles to prevent fatalities went mostly unchanged for about 50 years. Now, researchers are looking for better metrics to help prevent brain injuries&mdash;from mild concussions to traumatic damage.

In &ldquo;A Review of Head Injury Metrics Used in Automotive Safety and Sports Protective Equipment,&rdquo; published in the ASME Journal of Biomedical Engineering, authors Stefan Duma and Bethany Rowson examined every major metric that has been published over the past 60 years, including some of the original work done at Wayne State University in the 1960s and 1970s that examined skull fractures and were used for early football helmet and vehicle design standards. This effort summarizes existing head injury metrics and their applications for head and brain injuries.

Duma is Harry C. Wyatt Professor of Engineering and director of the Institute for Critical Technology and Applied Science (ICTAS) at Virginia Tech and Rowson is a former Virginia Tech research assistant professor. The team defined a metric as any variable or combination of variables that is &ldquo;used to assess injury severity, while a criterion is any quantitative value that is considered a threshold for injury or is assigned a predicted risk of injury.&rdquo;

The Virginia Tech team has about 30 years of history in automobile safety. About 20 years ago, they started working more in the sports and football area. Today, about 40 faculty and students at Virginia Tech work on brain-related research.

Advancing Head Injury Metrics Research

Researchers at Vanderbilt University have invented a nitrogen gas-powered thruster that is worn on the back that can correct falls as they start, restoring balance and averting potential injury.

<var>Researchers at Vanderbilt University have invented a nitrogen gas-powered thruster that is worn on the back that can correct falls as they start, restoring balance and averting potential injury.</var>

Falls can lead to severe and fatal injuries, particularly for elderly people. According to the U.S. Centers for Disease Control and Prevention, millions of people fall each year, with one in five suffering serious injury.

Michael Goldfarb, a professor of mechanical engineering at Vanderbilt University, has first-hand experience dealing with this health risk. &ldquo;As my parents grew older, both had experiences with fall risk that really limited their quality of life,&rdquo; he said. &ldquo;My father, in particular, had Parkinson&rsquo;s disease.&rdquo;

Goldfarb began thinking about new ways to correct occasional states of imbalance. Robotic exoskeletons can offer balance assistance, but have design challenges, such as having to coordinate a recovery response with the user. To avoid requiring a large frame or other structure (which would impede independence), he decided to focus on building a backpack-worn system that can apply forces directly to a person&rsquo;s body using a thruster.

&ldquo;This research challenge seemingly has not received much attention and therefore there were a lot of unknowns,&rdquo; Goldfarb said. &ldquo;Correcting a fall is a shared task between the person falling and the device helping to arrest the fall. What is the distribution of shared effort? How much force is appropriate to correct an impending fall? For how long is the force required? Can the magnitude of assistance required be provided by a compact cold-gas thruster?&rdquo;

Goldfarb and fellow researchers Almaskhan Baimyshev and Michael Finn-Henry then set out to create a lightweight, cold-gas thruster (CGT) jetpack that senses when a fall has been initiated and can provide a restoring force to help the person recover his or her balance.

Backpack Could Reduce the Risk of Fall

Paul P. Palies, director of the Combustion and Propulsion for Aviation Research Center at the University of Tennessee Space Institute, discusses the prospects for fueling aircraft with hydrogen.

Flying with Hydrogen

Ro-Bats, Bat-Bots, and Other Bat-like Robots

For these engineers, the allure of biologically inspired flight still remains strong.

January-March 2023

Geothermal cooling via a closed-loop thermal heat sink system shows promise in improving solar performance in hot regions.

Geothermal cooling via a closed-loop thermal heat sink system shows promise in improving solar performance in hot regions. 
 
Finding ways to enhance and improve the efficacy of photovoltaic (PV) systems is critical as the use of green power solutions continues to grow around the world. The concept behind one such solution to improve the performance of photovoltaic solar modules came to Ignacio Valiente-Blanco, a mechanical engineering professor in the Department of Signal Theory and Communications at the University of Alcalá (UAH) in Madrid, when he was hiking in the mountains near his home in Spain.

Cool Water Boosts Solar Efficiency 

Conductive flakes enable an economical additive manufacturing method to yield results.

Conductive flakes enable an economical additive manufacturing method to yield results. 
&nbsp; 
&nbsp; 
The standard manufacturing and assembly processes for heat exchangers can be expensive and time-consuming. They also limit the geometric configurations that can be considered during the design process. 
Additive manufacturing (AM), when viable, can be a more efficient manufacturing process and gives engineers much more design freedom, often allowing them to create features that standard machining cannot. 
Researchers are looking for ways to build high-performance heat exchangers using AM. However, most metal-based AM processes are so expensive that commercial production is not viable. 
Looking to see if another approach might work, a research team led by Gregory F. Nellis, a professor at the University of Wisconsin (UW), designed and built an efficient and cost-effective heat exchanger using lower-cost, deposition-based AM processes. The team successfully printed a heat exchanger using fused deposition modeling that has sufficient thermal conductivity to outperform standard heat exchangers, at a more affordable cost.

Printing Better, Cheaper Heat Exchangers

Using Smart Trains to Find Defective Rails

Francesco Lanza di Scalea, professor of experimental mechanics, NDE and SHM Laboratory, Department of Structural Engineering, University of California, San Diego, La Jolla, Calif., discusses the use of ultrasonic high-speed inspection of train track rails to detect internal defects and potentially avoid costly damages.

Better Grip for Laparoscopy

To pull objects from the tightest spaces, researchers devise a clever little claw.

April-June 2023

Using pneumatic pressure inside of the tube to keep it open, researchers develop a new way to manufacture glass components.

Silicate-based glasses have several physical and chemical properties that make them preferred manufacturing materials, such as high thermal and chemical stability, stiffness, and high optical transparency. They are also relatively low cost. 
&nbsp; 
However, glasses can also be hard to work with; For example, there are difficulties in precisely controlling heat and pressure. The standard methods for making glass objects tend to be slow and expensive, especially for more complex pieces and shapes that take more time and require greater precision. 
&nbsp; 
These challenges might compel engineers to try established additive manufacturing (AM) technologies instead for creating transparent glass pieces; however, these methods also have material challenges (for example, the high molten viscosity of glass limits bubble consolidation and release in powder bed processes).

3D Printing with Glass Tubes

The efficiency of wind turbines depends on how smoothly they can slice through the air. Can combining new blade shapes produce superior results?

Over the past two decades, wind power has become an increasingly important source of electricity worldwide, and large, three-bladed turbines are a familiar sight. While most of those blades are formed as a simple airfoil, researchers have been studying whether new shapes could yield great performance.

Cutting Through the Wind

Miguel Hoffmann and Alaa Elwany of Texas A&amp;M University discuss the prospect of manufacturing in orbit and beyond.

Use of additive manufacturing (AM) has exploded since its conception over 40 years ago. With more and more eyes looking skyward, from space tourism to NASA&rsquo;s return to the moon, the potential AM holds for use in orbit and beyond is notable.

Manufacturing Among the Stars

Mouthpieces Measure Movement with Precision

NASCAR drivers help Wake Forest researchers collect better data to measure drivers&#39; exposure to acceleration and vibration.

Stock car racing fans like to listen to &ldquo;mic&rsquo;d up&rdquo; drivers. But how about when NASCAR drivers sport custom-made mouthpieces to pick up more than action reactions? 
&nbsp; 
To collect real-time data on exposure to acceleration and vibrations, about half of all NASCAR drivers &ldquo;put instrumented, custom-fit mouthpieces inside their mouths,&rdquo; explained Joel Stitzel, a professor of biomedical engineering at the Wake Forest University School of Medicine in Winston-Salem, N.C. 
&nbsp; 
This helps researchers collect kinematics of drivers&rsquo; experience when performing practice laps or on race day. The results were released in the paper, &ldquo;Pilot Collection and Evaluation of Head Kinematics in Stock Car Racing,&rdquo; published in the March 2023 issue of Journal of Biomechanical Engineering.

NASCAR drivers help Wake Forest researchers collect better data to measure drivers&#39; exposure to acceleration and vibration.

July-September 2023

Can hydrogen reduce the carbon footprint of power plants? Researcher have found that conventional gas turbines can operate safely with a 30 percent hydrogen mix.

Many experts believe burning hydrogen with natural gas can reduce carbon emissions without negatively impacting operational efficiency and performance. Hydrogen co-firing in a gas turbine ought to lower the carbon footprint of existing thermal power generation or co-generation plants by injecting hydrogen into the existing natural gas grid. At the moment, however, the scientific data on the co-combustion of hydrogen and natural gas in gas turbines in an industrial environment is sparse. 
 
To fill in the knowledge gaps, a team of researchers co-fired hydrogen and conventional natural gas in an ENGIE-owned Siemens SGT-600 (Alstom legacy GT10B) 24-MW industrial gas turbine in Antwerp. Their results were revealed in the paper, &ldquo;Demonstration of Natural Gas and Hydrogen Cocombustion in an Industrial Gas Turbine,&rdquo; published in the April 2023 Journal of Engineering for Gas Turbines and Power. 
&nbsp;

Hydrogen-Natural Gas Co-Combustion Reduces Carbon Emissions 

NIOSH scientists develop model confirming rates of fresh air flow needed to help trapped miners survive.

Underground miners work in dangerous conditions, threatened by tunnel collapse, fires, and explosions. In 2006, three major coal mining accidents occurred, either from explosions or fire, and 19 miners died. As a result, Congress passed the Mine Improvement and New Emergency Response Act of 2006, more commonly known as the MINER Act. That law tasked the National Institute for Occupational Safety and Health (NIOSH) with researching and testing refuge alternatives in mines in the event of another disaster. 
 
One of the main charges investigated by NIOSH&rsquo;s Office of Mine Safety and Health Research was investigating the practicality, survivability, and cost of refuge alternatives, basically a secure area where miners can flee in the event of life-threatening accidents. The researchers found that built-in-place (BIP) and portable refuge alternatives were practical in most underground coal mines as a refuge of last resort, with BIP refuges a better option.

Keeping Trapped Miners Safe

Predictive Model Forecasts Hurricane Impacts to Refineries

Jamie E. Padgett and Kendall M. Capshaw of Rice University discuss ways to better understand how weather impacts the oil industry.

The U.S. Gulf Coast is home to more than half of total U.S. refining capacity. But given the area&rsquo;s vulnerability to hurricanes, weather-related stoppages and slowdowns weigh heavily on the nation&rsquo;s supply of petroleum products.

Researchers at Rice University in Houston have proposed development of a predictive model for the likelihood and expected duration of refinery shutdowns under hurricane hazards. Their work is described in &ldquo;Development and Application of a Predictive Model for Estimating Refinery Shutdown Duration and Resilience Impacts Due to Hurricane Hazards,&rdquo; published in the September 2023 issue of the ASCE-ASME Journal of Risk and Uncertainty in Engineering Systems, Part B: Mechanical Engineering.

Origami Inchworm

A new soft robot design relies on the folding and unfolding of origami cylinders to move reliably across surfaces.

October-December 2023

Air Force engineers 3D print turbine blades suitable for a drone engine.

Engineers are always trying to squeeze more power out of engines, and those in the military have added incentive. Military researchers looking to increase the power and thrust of a commercial compact jet engine turned to ceramics to meet the increased turbine inlet temperature that prevented them from using metals. Using finite element analysis and 3D printing, they showed that a turbine rotor made of silicon nitride could handle the higher temperatures and still provide increased power and thrust. 
 
&ldquo;We wanted to take something that was a small-scale engine that was already fairly power-dense to begin with and try to make it more power dense,&rdquo; said U.S. Air Force Lt. Col. Brian Bohan. &ldquo;There&rsquo;s a big gap in the commercial sector for this scale. We were trying to come up with ways to make an engine as powerful as some of the more expensive military engines, but at a more cost-effective price point.&rdquo;

Ceramic Boost for Small Jet Engines

To the annoyance of parents everywhere, children love playing with tape measures. They will lock the extended tape in place and notice how a slight curve keeps the metal strip rigid. Then they will release the lock and delight in how a spring retracts the tape with a satisfying thwack. 
 
Roboticists at the University of California, Los Angeles have been playing with tape measures, too. They have discovered that the rigid but bendy tape can be used as a new type of limb that acts something like a spider monkey&rsquo;s arm or an octopus&rsquo;s tentacle.

A new type of robotic arm takes its inspiration from the toolbox favorite.

Made to Measure

Scarlett Miller of Penn State discusses how engineering teams can build psychological safety in their members.

Members of teams with high levels of psychological safety feel free to express ideas and opinions. This feeling of safety promotes creativity and innovation. However, little evidence exists that shows how best to facilitate or build psychological safety within teams, especially in an educational context. Scarlett Miller, professor of engineering design and industrial engineering and director of the Center for Research in Design and Innovation at The Pennsylvania State University, recently led a team of researchers that published a study on this topic in the ASME Journal of Mechanical Design. She discusses the impact of interventions aimed at improving psychological safety in engineering design student teams.

Comfortable Enough to Innovate

Frigid temperatures can be lethal. New research sets a baseline for manufacturers developing insulated fabrics.

Extremely cold, sub-zero weather conditions can kill, even after only a short time. Poorly insulated clothing can result in life-threatening respiratory and cardiovascular problems, as well as frostbite and hypothermia. 
 
People survive longer in severe cold if they wear clothing and outerwear that are specially designed for cold-weather conditions. Knowing the amount of a time a person can survive for a set of environmental conditions is critical for developing new fabrics and clothing that extend survival time. 
 
To improve the design of advanced, cold-weather fabrics, researchers at the Department of Mechanical Engineering at the Indian Institute of Technology in New Delhi undertook a series of experiments to evaluate how three key factors&mdash;ambient temperature, fabric insulation, and metabolic heat (heat generated by a person as a function of the physical work performed)&mdash;impact survival time. Their research is described in a paper published by the Journal of Heat and Mass Transfer in July 2023.

Surviving the Cold

January-March 2024

Energy output of vertical bifacial solar panel arrays can be vastly improved with the help of specific design considerations.

Most large-scale solar power facilities are huge fixed-tilt installations, with rows upon rows of them covering acres of land. But a newer concept is agrivoltaics, which involves installing solar panels on land already in use for agriculture or livestock. Making the most of such space has led to the development of a novel solar installation geometry, called the vertical bifacial (VBF) array, which was pioneered by German company Next2Sun. 
 
Unlike the massive fixed-tilt installations that require large steel canopies to hold photovoltaic panels above the ground, as their name suggests, VBF panels have an upright orientation and are installed closer to the surface. These walls of panels allow for easier passage of machinery, animals, and people without the need to worry about clearance height, effectively increasing both the land&rsquo;s usage and the owner&rsquo;s return on investment.

Two-Sided Panel Optimizes Agrivoltaics

Researchers find that a blow to the side of the head causes more potential brain injury that one that hits straight-on.

Due to its visibility in athletes and returned service members, traumatic brain injury (TBI) has received widespread attention. But it&rsquo;s an injury that is still poorly understood. While studies suggest that some people are more vulnerable to TBI than others or that the direction of head motion and the nature of the impact affects the chances of injury, these ideas have not yet been confirmed by studying human brain motion. 
 
Now, engineers at Washington University in St. Louis have designed an experiment using magnetic resonance elastography (MRE) that directly assesses how skull motion direction impacts in vivo human brain deformation.

Direct Impact

Tools that act like ChatGPT could help engineers digest large stacks of information.

Chatbots that are trained on a set of human-generated writing samples and can reply to prompts with sentences and even paragraphs that mimic their training, have become familiar to most users of the internet. One of these models, ChatGPT, is familiar enough that it&rsquo;s how most people understand large language models (LLM) that seemingly learn, comprehend, and then generate language. But these models also may carry great promise for the physical sciences, including applied mechanics. 
 
That&rsquo;s the premise of a paper written by a team of researchers from the University of California, Santa Barbara; University of New Hampshire; and Northwestern University. &ldquo;These emergent capabilities are exciting for science because they vastly lower the barrier to effective scientific data mining,&rdquo; they wrote in &ldquo;Perspective: Large Language Models in Applied Mechanics.&rdquo; The article appeared in the October 2023 issue of the ASME Journal of Applied Mechanics.

How Language Models May Shape Engineering

Engineers studied which types of falls caused the most serious injuries for riders.

Crashing Electric Scooters

April-June 2024

To improve the communication between patients and bioelectronic devices, the interface between the two should follow the curve of the body. Researchers have developed a curvature-matching design strategy that can enhance wearability during skin motion.

Skin-based bioelectronics applications are becoming more common in healthcare markets, but one challenge is keeping these devices in contact with bodies that are in constant motion. This conformal contact with the skin allows for bio-signal acquisition, especially for curvilinear areas of the body, so that the devices can send health data to external networks.&nbsp; 
 
Raudel Avila, assistant professor of mechanical engineering at Rice University, was determined to develop an improved geometrical and mechanical design for bioelectronics that improves wearability, efficiency, and comfort. &nbsp;

Contact is Key to Bioelectronics

A combo of wireless sensors and computer models reveals bridge integrity issues unseen by conventional inspections.

Bridge safety may be improved by using remote wireless sensors and finite element models for structural health monitoring (SHM) by providing a fuller picture of bridge integrity. This is according to a recently published study from the University of Pittsburgh&#39;s Swanson School of Engineering. &nbsp; 
 
Led by Piervincenzo (Piero) Rizzo, associate professor of civil and environmental engineering, the researchers compared model data to field data gathered from three similar concrete box bridges with existing wireless sensors. The team compared those field results against finite element models, which simulate various loading or impact conditions, including the vibrations, displacement, and deformation a truck creates. &nbsp;

Diagnosing Bridge Health

Engineers are finding a growing number of applications for mechanical metamaterials, which feature unique mechanical properties that are determined by their structure.

Researchers Hanxun Jin and Horacio D. Espinosa recently examined some advances in self-assembly techniques that have the potential to fabricate load-bearing mechanical metamaterials in &ldquo;Mechanical Metamaterials Fabricated From Self-Assembly: A Perspective,&rdquo; published in April in the ASME Journal of Applied Mechanics.&nbsp; 
 
Espinosa is a professor in the Department of Mechanical Engineering at Northwestern University. Jin was a postdoctoral researcher in the Division of Engineering and Applied Science at the California Institute of Technology when the paper was published; currently, Jin is a senior research scientist at Washington University in St. Louis.&nbsp;

Engineers are finding a growing number of applications for mechanical metamaterials, which feature unique properties that are determined by their structure.

Fabricating Mechanical Metamaterials

The horizontal-axis wind turbine has become an efficient and economical means to produce electricity. Some of the largest machines can produce as much as 15 MW when running at full capacity. But such turbines can be too complicated for small-scale operations or for capturing wind power in urban settings.&nbsp;

One popular alternative is the vertical-axis wind turbine that utilizes the Savonius design, which features a pair of simple hollow half cylinders.

The horizontal-axis wind turbine has become an efficient and economical means to produce electricity. Some of the largest machines can produce as much as 15 MW when running at full capacity. But such turbines can be too complicated for small-scale operations or for capturing wind power in urban settings.

A Better Shape to Catch the Wind

October-December 2024

The technology has uses beyond the aviation and manufacturing sectors. A new study found all three phases of civil engineering projects&mdash;planning/design, construction, and operation and maintenance&mdash;can find value in digital twins.

Digital twin technology (DT) has been successfully deployed in fields as varied as aviation, manufacturing, and oil and gas. But civil engineering, especially for field-related applications, has not been a venue for DT, in part because it relies on a variety of external technologies and approaches that were developed for other engineering fields. The most frequent and consistent use of DT in civil engineering projects is in the operations and maintenance phase, whereas building information modeling (BIM) is pervasively utilized in the first phase of planning/design.

Digital Twins Can Support Civil Engineering Projects

Researchers at the University of Bologna in Italy have developed a method of dry grinding for automotive gears&mdash;without using oils and other lubricants.

Gears are key components in automotive transmissions. Electrification of automotive powertrains over the coming years will pressure gear manufacturers to increase gear production. Any improvements that can maximize efficiency in the gear production chain will be in high demand for keeping up with market growth and reducing production costs. &nbsp; 
 
One way to do this is by improving the gear-grinding process. Grinding is important because it eliminates surface flaws, maximizes load capacity, and minimizes running noise. However, standard grinding of high-performance gears is a &ldquo;wet&rdquo; process&rdquo; that is time-consuming and requires multiple steps. Wet grinding typically uses a large amount of lubricant. Energy consumption for lubrification and cooling represents almost two-thirds of the total energy consumption of a typical grinding machining center&mdash;a cost that gear manufacturers would love to eliminate.

A More Sustainable Way to Make Automotive Gears

Manufacturers rely on heating, cooling, and ventilation systems to provide optimal environments for their equipment&mdash;and workers. University of Alabama researcher Forooza Samadi describes ways companies can optimize these systems.

The first large-scale implementation of an air-conditioning system was at the Sackett-Wilhelms Lithographing &amp; Publishing Company in Brooklyn in 1902, which used the then-new invention to limit the amount of moisture absorbed by paper. Today, most factories are climate controlled. But not all factory owners optimize their heating, ventilation, and air conditioning (HVAC) systems for energy efficiency. &nbsp; 
 
Forooza Samadi, assistant director of the Alabama Industrial Training and Assessment Center and assistant professor of mechanical engineering at the University of Alabama in Tuscaloosa, recently studied ways factories could cut costs and carbon emissions. She was coauthor on the paper, &ldquo;Strategic Evaluation of Sustainable Practices for HVAC Systems in Small- and Medium-Sized U.S. Manufacturers,&rdquo; published in the ASME Journal of Engineering for Sustainable Buildings and Cities in August 2024. Here, she described some of her findings.

Q&A: Improving Efficiency in HVAC Systems

It&rsquo;s not all about power&mdash;a robotic arm needs the right technique and architecture to hurl an object efficiently.

Robot Throwing

January-March 2025

Researchers have devised a way to use acoustic levitation to enable metal additive manufacturing in microgravity environments in space, where metal powders can be fused together to create accurate parts and components.

For astronauts on long-duration space flights, the nearest supply depot would be millions of miles away. On such journeys, in-space manufacturing (ISM) could be a time- and cost-efficient way to manufacture tools, components, and infrastructure, as well as repair defective components or large structures. ISM could be conducted in transit, in orbit, and on the surface of extraterrestrial bodies. &nbsp; 
 
Metal additive manufacturing (AM) is likely the best method for creating these parts in space. Compared to packing metal parts and materials into the spacecraft, making them on board would be a huge logistical benefit. However, many conventional gravity-dominated methods cannot be carried out in space, including AM methods. For example, powder-based selective laser melting (SLM) exhibits the same problem&mdash;neither the feed materials, or printed parts, can be held in place by gravity. &nbsp;

Researchers have devised a way to use acoustic levitation to enable metal additive manufacturing in microgravity environments in space, where metal powders can be fused together to create accurate parts and components.&nbsp;

Space Manufacturing Could Need Acoustic Levitation 

When a ballistic shield is struck with a heavy object, it can actually bend backward toward the shield holder. Researchers want to know if these shields do enough to protect against arm injury.

Ballistic shields are used by law enforcement personnel to manage crowd control and protect infrastructure. These shields are physically supported by a user&rsquo;s arm to protect against projectile attacks or other weaponry. Although these shields are effective at stopping the projectile itself, a backward deflection of the shield may cause injury to areas along the upper extremity that are in contact with the shield. These kinds of injuries, caused by the rapid deformation of protective equipment from projectiles, can be severe.&nbsp; 
 
Researchers have wanted to determine how well these shields protect against upper extremity fractures. &nbsp;

When a ballistic shield is struck with a heavy object, it can actually bend backward toward the shield holder. Researchers want to know if these shields do enough to protect against arm injury.&nbsp;

How Well Do Shields Protect? 

Yes, says Bechel&rsquo;s John Gülen, but probably not in some of the carbon-neutral applications that have received attention over the past decade.

Gas turbines are amazing machines&mdash;both incredibly efficient and relatively inexpensive to purchase and operate. But in most electric power applications, the fuel of choice is natural gas, which produces carbon dioxide when combusted. Given that many governments around the world have set deadlines for eliminating carbon emissions from electric production, the gas turbine industry has been looking at applications where carbon is removed from the fuel or captured from the exhaust and sequestered. 
 
S. Can &ldquo;John&rdquo; Gülen, an ASME Fellow who is Senior Principal Engineer at the Engineering Technology Group of Bechtel Infrastructure and Power, is an internationally recognized expert in power technologies. In October 2024, he (together with Bechtel&rsquo;s Martin Curtis) published a paper in the Journal of Engineering for Gas Turbines and Power called &ldquo;Gas Turbine&rsquo;s Role in Energy Transition,&rdquo; that examined the prospects for some of these new applications.

Does the Energy Transition Have a Place for Gas Turbines?

Electronics has its microtransistors. Now a research team has created a microscale valve for controlling fluid flows.

Microfluidics, which controls the flow of minuscule amounts of liquids, has found important applications in research biology, medicine, and even food science. While clever designs of microfluidic valves have enabled engineers to create rudimentary microfluidic &ldquo;logic,&rdquo; these passive microscale valves don&rsquo;t have the power of hydraulic &ldquo;fluid logic&rdquo; systems, let alone microelectronics.&nbsp;

July-September 2024

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Synthetic Bone Versus Reality

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What Makes a CAD Expert?

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Design to Disassemble

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The Creeping Claw

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