Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International



Home > Press > Engineers fabricate a chip-free, wireless electronic “skin”: The device senses and wirelessly transmits signals related to pulse, sweat, and ultraviolet exposure, without bulky chips or batteries

MIT engineers fabricated a chip-free, wireless electronic “skin.” The device senses and wirelessly transmits signals related to pulse, sweat, and ultraviolet exposure, without bulky chips or batteries.
CREDIT
Courtesy of the researchers
MIT engineers fabricated a chip-free, wireless electronic “skin.” The device senses and wirelessly transmits signals related to pulse, sweat, and ultraviolet exposure, without bulky chips or batteries. CREDIT Courtesy of the researchers

Abstract:
Wearable sensors are ubiquitous thanks to wireless technology that enables a person’s glucose concentrations, blood pressure, heart rate, and activity levels to be transmitted seamlessly from sensor to smartphone for further analysis.

Engineers fabricate a chip-free, wireless electronic “skin”: The device senses and wirelessly transmits signals related to pulse, sweat, and ultraviolet exposure, without bulky chips or batteries

Cambridge, MA | Posted on August 19th, 2022

Most wireless sensors today communicate via embedded Bluetooth chips that are themselves powered by small batteries. But these conventional chips and power sources will likely be too bulky for next-generation sensors, which are taking on smaller, thinner, more flexible forms.

Now MIT engineers have devised a new kind of wearable sensor that communicates wirelessly without requiring onboard chips or batteries. Their design, detailed today in the journal Science, opens a path toward chip-free wireless sensors.

The team’s sensor design is a form of electronic skin, or “e-skin” — a flexible, semiconducting film that conforms to the skin like electronic Scotch tape. The heart of the sensor is an ultrathin, high-quality film of gallium nitride, a material that is known for its piezoelectric properties, meaning that it can both produce an electrical signal in response to mechanical strain and mechanically vibrate in response to an electrical impulse.

The researchers found they could harness gallium nitride’s two-way piezoelectric properties and use the material simultaneously for both sensing and wireless communication.

In their new study, the team produced pure, single-crystalline samples of gallium nitride, which they paired with a conducting layer of gold to boost any incoming or outgoing electrical signal. They showed that the device was sensitive enough to vibrate in response to a person’s heartbeat, as well as the salt in their sweat, and that the material’s vibrations generated an electrical signal that could be read by a nearby receiver. In this way, the device was able to wirelessly transmit sensing information, without the need for a chip or battery.

“Chips require a lot of power, but our device could make a system very light without having any chips that are power-hungry,” says the study’s corresponding author, Jeehwan Kim, an associate professor of mechanical engineering and of materials science and engineering, and a principal investigator in the Research Laboratory of Electronics.

“You could put it on your body like a bandage, and paired with a wireless reader on your cellphone, you could wirelessly monitor your pulse, sweat, and other biological signals.”

Kim’s co-authors include first author and former MIT postdoc Yeongin Kim, who is now an assistant professor at the University of Cincinnati; co-corresponding author Jiyeon Han of the Korean cosmetics company AMOREPACIFIC, which helped motivate the current work; members of the Kim Research Group at MIT; and other collaborators at the University of Virginia, Washington University in St. Louis, and multiple institutions across South Korea.

Pure resonance

Jeehwan Kim’s group previously developed a technique, called remote epitaxy, that they have employed to quickly grow and peel away ultrathin, high-quality semiconductors from wafers coated with graphene. Using this technique, they have fabricated and explored various flexible, multifunctional electronic films.

In their new study, the engineers used the same technique to peel away ultrathin single-crystalline films of gallium nitride, which in its pure, defect-free form is a highly sensitive piezoelectric material.

The team looked to use a pure film of gallium nitride as both a sensor and a wireless communicator of surface acoustic waves, which are essentially vibrations across the films. The patterns of these waves can indicate a person’s heart rate, or even more subtly, the presence of certain compounds on the skin, such as salt in sweat.

The researchers hypothesized that a gallium nitride-based sensor, adhered to the skin, would have its own inherent, “resonant” vibration or frequency that the piezoelectric material would simultaneously convert into an electrical signal, the frequency of which a wireless receiver could register. Any change to the skin’s conditions, such as from an accelerated heart rate, would affect the sensor’s mechanical vibrations, and the electrical signal that it automatically transmits to the recever.

“If there is any change in the pulse, or chemicals in sweat, or even ultraviolet exposure to skin, all of this activity can change the pattern of surface acoustic waves on the gallium nitride film,” notes Yeongin Kim. “And the sensitivity of our film is so high that it can detect these changes.”

Wave transmission

To test their idea, the researchers produced a thin film of pure, high-quality gallium nitride and paired it with a layer of gold to boost the electrical signal. They deposited the gold in the pattern of repeating dumbbells — a lattice-like configuration that imparted some flexibility to the normally rigid metal. The gallium nitride and gold, which they consider to be a sample of electronic skin, measures just 250 nanometers thick — about 100 times thinner than the width of a human hair.

They placed the new e-skin on volunteers’ wrists and necks, and used a simple antenna, held nearby, to wirelessly register the device’s frequency without physically contacting the sensor itself. The device was able to sense and wirelessly transmit changes in the surface acoustic waves of the gallium nitride on volunteers’ skin related to their heart rate.

The team also paired the device with a thin ion-sensing membrane — a material that selectively attracts a target ion, and in this case, sodium. With this enhancement, the device could sense and wireless transmit changing sodium levels as a volunteer held onto a heat pad and began to sweat.

The researchers see their results as a first step toward chip-free wireless sensors, and they envision that the current device could be paired with other selective membranes to monitor other vital biomarkers.

“We showed sodium sensing, but if you change the sensing membrane, you could detect any target biomarker, such as glucose, or cortisol related to stress levels,” says co-author and MIT postdoc Jun Min Suh. “It’s quite a versatile platform.”

###

This research was supported by AMOREPACIFIC.

####

For more information, please click here

Contacts:
Sarah McDonnell
Massachusetts Institute of Technology

Office: 617-253-8923
Cell: 617-460-9583

Copyright © Massachusetts Institute of Technology

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

ARTICLE TITLE

Related News Press

News and information

HKUST researchers develop a novel integration scheme for efficient coupling between III-V and silicon November 18th, 2022

Researchers at Purdue unlock light-matter interactions on sub-nanometer scales, leading to ‘picophotonics’ November 18th, 2022

Rice turns asphaltene into graphene for composites: ‘Flashed’ byproduct of crude oil could bolster materials, polymer inks November 18th, 2022

How “2D” materials expand: New technique that accurately measures how atom-thin materials expand when heated could help engineers develop faster, more powerful electronic devices November 18th, 2022

Wearable electronics

Underwater movement sensor alerts when a swimmer might be drowning October 7th, 2022

Disposable electronics on a simple sheet of paper October 7th, 2022

New chip ramps up AI computing efficiency August 19th, 2022

Researchers design new inks for 3D-printable wearable bioelectronics: Potential uses include printing electronic tattoos for medical tracking applications August 19th, 2022

Possible Futures

HKUST researchers develop a novel integration scheme for efficient coupling between III-V and silicon November 18th, 2022

NIST’s grid of quantum islands could reveal secrets for powerful technologies November 18th, 2022

A new experiment pushes the boundaries of our understanding of topological quantum matter: The behavior of bosonic particles observed in a magnetic insulator fabricated from ruthenium chloride can be explained by a relatively new and little-studied physics phenomenon called the B November 18th, 2022

Trial by wind: Testing the heat resistance of carbon fiber-reinforced ultra-high-temperature ceramic matrix composites: Researchers use an arc-wind tunnel to test the heat resistance of carbon fiber reinforced ultra-high-temperature ceramic matrix composites November 18th, 2022

Chip Technology

NIST’s grid of quantum islands could reveal secrets for powerful technologies November 18th, 2022

An on-chip time-lens generates ultrafast pulses: New device opens the doors to applications in communication, quantum computing, astronomy November 18th, 2022

Researchers at Purdue unlock light-matter interactions on sub-nanometer scales, leading to ‘picophotonics’ November 18th, 2022

Semi-nonlinear etchless lithium niobate waveguide with bound states in the continuum November 4th, 2022

Nanomedicine

Cutting-edge combination shows promise in patients with chemotherapy-resistant urothelial cancer November 4th, 2022

Advanced nanoparticles provide new weapon to fight difficult cancers: Researchers use nanoparticles to deliver a bacterially derived compound that targets the STING pathway to suppress tumor growth and metastasis by disrupting blood vessels and stimulating immune response October 28th, 2022

Smart materials: metal cations-recognizable thermoresponsive polymers: Osaka Metropolitan University scientists developed a novel polymer, the thermoresponsiveness of which can easily be regulated by changing the type and mixing ratio of ionic species October 14th, 2022

Quantum-Si’s next-generation single-molecule protein sequencing technology published in Science, signaling new era of life science and biomedical research: Semiconductor chip and Time Domain Sequencing™ technology will advance drug discovery and diagnostics, enabling people to li October 14th, 2022

Sensors

Spin photonics to move forward with new anapole probe November 4th, 2022

New $1.25 million research project will map materials at the nanoscale: The work can lead to new catalysts and other compounds that could be applicable in a range of areas including quantum science, renewable energy, life sciences and sustainability October 28th, 2022

Highly sensitive and fast response strain sensor based on evanescently coupled micro/nanofibers October 14th, 2022

Taking salt out of the water equation October 7th, 2022

Discoveries

An on-chip time-lens generates ultrafast pulses: New device opens the doors to applications in communication, quantum computing, astronomy November 18th, 2022

Researchers at Purdue unlock light-matter interactions on sub-nanometer scales, leading to ‘picophotonics’ November 18th, 2022

Rice turns asphaltene into graphene for composites: ‘Flashed’ byproduct of crude oil could bolster materials, polymer inks November 18th, 2022

How “2D” materials expand: New technique that accurately measures how atom-thin materials expand when heated could help engineers develop faster, more powerful electronic devices November 18th, 2022

Announcements

HKUST researchers develop a novel integration scheme for efficient coupling between III-V and silicon November 18th, 2022

NIST’s grid of quantum islands could reveal secrets for powerful technologies November 18th, 2022

A new experiment pushes the boundaries of our understanding of topological quantum matter: The behavior of bosonic particles observed in a magnetic insulator fabricated from ruthenium chloride can be explained by a relatively new and little-studied physics phenomenon called the B November 18th, 2022

How “2D” materials expand: New technique that accurately measures how atom-thin materials expand when heated could help engineers develop faster, more powerful electronic devices November 18th, 2022

Nanobiotechnology

Cutting-edge combination shows promise in patients with chemotherapy-resistant urothelial cancer November 4th, 2022

Advanced nanoparticles provide new weapon to fight difficult cancers: Researchers use nanoparticles to deliver a bacterially derived compound that targets the STING pathway to suppress tumor growth and metastasis by disrupting blood vessels and stimulating immune response October 28th, 2022

Smart materials: metal cations-recognizable thermoresponsive polymers: Osaka Metropolitan University scientists developed a novel polymer, the thermoresponsiveness of which can easily be regulated by changing the type and mixing ratio of ionic species October 14th, 2022

Quantum-Si’s next-generation single-molecule protein sequencing technology published in Science, signaling new era of life science and biomedical research: Semiconductor chip and Time Domain Sequencing™ technology will advance drug discovery and diagnostics, enabling people to li October 14th, 2022

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project