Tag Archives: sensor

Artificial Skin Opens SuperHuman Perception

A new type of sensor could lead to artificial skin that someday helps burn victimsfeel’ and safeguards the rest of us, University of Connecticut (UConn)  researchers suggest in a paper in Advanced Materials.

Our skin’s ability to perceive pressure, heat, cold, and vibration is a critical safety function that most people take for granted. But burn victims, those with prosthetic limbs, and others who have lost skin sensitivity for one reason or another, can’t take it for granted, and often injure themselves unintentionally. Chemists Islam Mosa from UConn, and James Rusling from UConn and UConn Health, along with University of Toronto engineer Abdelsalam Ahmed, wanted to create a sensor that can mimic the sensing properties of skin. Such a sensor would need to be able to detect pressure, temperature, and vibration. But perhaps it could do other things too, the researchers thought.

It would be very cool if it had abilities human skin does not; for example, the ability to detect magnetic fields, sound waves, and abnormal behaviors,” said Mosa.

Mosa and his colleagues created such a sensor with a silicone tube wrapped in a copper wire and filled with a special fluid made of tiny particles of iron oxide just one billionth of a meter long, called nanoparticles. The nanoparticles rub around the inside of the silicone tube and create an electric current. The copper wire surrounding the silicone tube picks up the current as a signal. When this tube is bumped by something experiencing pressure, the nanoparticles move and the electric signal changes. Sound waves also create waves in the nanoparticle fluid, and the electric signal changes in a different way than when the tube is bumped.

The researchers found that magnetic fields alter the signal too, in a way distinct from pressure or sound waves. Even a person moving around while carrying the sensor changes the electrical current, and the team found they could distinguish between the electrical signals caused by walking, running, jumping, and swimming.

Metal skin might sound like a superhero power, but this skin wouldn’t make the wearer Colossus from the X-men. Rather, Mosa and his colleagues hope it could help burn victimsfeelagain, and perhaps act as an early warning for workers exposed to dangerously high magnetic fields. Because the rubber exterior is completely sealed and waterproof, it could also serve as a wearable monitor to alert parents if their child fell into deep water in a pool, for example.

Source: https://today.uconn.edu/

Electronic Skin To Restore Sense Of Pain

Amputees often experience the sensation of a “phantom limb”—a feeling that a missing body part is still there. That sensory illusion is closer to becoming a reality thanks to a team of engineers at the Johns Hopkins University that has created an electronic skin. When layered on top of prosthetic hands, this e-dermis brings back a real sense of touch through the fingertips.

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After many years, I felt my hand, as if a hollow shell got filled with life again,” says the anonymous amputee who served as the team’s principal volunteer tester.

Made of fabric and rubber laced with sensors to mimic nerve endings, e-dermis recreates a sense of touch as well as pain by sensing stimuli and relaying the impulses back to the peripheral nerves.

We’ve made a sensor that goes over the fingertips of a prosthetic hand and acts like your own skin would,” explains Luke Osborn, a graduate student in biomedical engineering. “It’s inspired by what is happening in human biology, with receptors for both touch and pain“This is interesting and new,” Osborn adds, “because now we can have a prosthetic hand that is already on the market and fit it with an e-dermis that can tell the wearer whether he or she is picking up something that is round or whether it has sharp points.”

The work in the journal Science Robotics – shows it is possible to restore a range of natural, touch-based feelings to amputees who use prosthetic limbs. The ability to detect pain could be useful, for instance, not only in prosthetic hands but also in lower limb prostheses, alerting the user to potential damage to the device.

Human skin contains a complex network of receptors that relay a variety of sensations to the brain. This network provided a biological template for the research team, which includes members from the Johns Hopkins departments of Biomedical Engineering, Electrical and Computer Engineering, and Neurology, and from the Singapore Institute of Neurotechnology.

Bringing a more human touch to modern prosthetic designs is critical, especially when it comes to incorporating the ability to feel pain, Osborn states. “Pain is, of course, unpleasant, but it’s also an essential, protective sense of touch that is lacking in the prostheses that are currently available to amputees,” he says. “Advances in prosthesis designs and control mechanisms can aid an amputee’s ability to regain lost function, but they often lack meaningful, tactile feedback or perception.

Source: http://releases.jhu.edu/

Strain Improves Performance of Atomically Thin Semiconductor

Researchers in UConn’s Institute of Materials Science significantly improved the performance of an atomically thin semiconductor material by stretching it, an accomplishment that could prove beneficial to engineers designing the next generation of flexible electronics, nano devices, and optical sensors.

In a study appearing in the research journal Nano Letters, Michael Pettes, assistant professor of mechanical engineering, reports that a six-atom thick bilayer of tungsten diselenide exhibited a 100-fold increase in photoluminescence when it was subjected to strain. The material had never exhibited such photoluminescence before.

The findings mark the first time scientists have been able to conclusively show that the properties of atomically thin materials can be mechanically manipulated to enhance their performance, Pettes says. Such capabilities could lead to faster computer processors and more efficient sensors.

The process the researchers used to achieve the outcome is also significant in that it offers a reliable new methodology for measuring the impact of strain on ultrathin materials, something that has been difficult to do and a hindrance to innovation.

Experiments involving strain are often criticized since the strain experienced by these atomically thin materials is difficult to determine and often speculated as being incorrect,” says Pettes. “Our study provides a new methodology for conducting strain-dependent measurements of ultrathin materials, and this is important because strain is predicted to offer orders of magnitude changes in the properties of these materials across many different scientific fields.”

Source: https://today.uconn.edu/