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

Stability of perovskite solar cells reaches next milestone January 27th, 2023

Qubits on strong stimulants: Researchers find ways to improve the storage time of quantum information in a spin rich material January 27th, 2023

UCF researcher receives Samsung International Global Research Outreach Award: The award from the multinational electronics corporation will fund the development of infrared night vision and thermal sensing camera technology for cell phones and consumer electronics January 27th, 2023

Temperature-sensing building material changes color to save energy January 27th, 2023

Wearable electronics

Vertical electrochemical transistor pushes wearable electronics forward: Biomedical sensing is one application of efficient, low-cost transistors January 20th, 2023

Tin selenide nanosheets enables to develop wearable tracking devices December 9th, 2022

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

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

Possible Futures

One of the causes of aggressive liver cancer discovered: a 'molecular staple' that helps repair broken: DNA Researchers describe a new DNA repair mechanism that hinders cancer treatment January 27th, 2023

Stability of perovskite solar cells reaches next milestone January 27th, 2023

Danish quantum physicists make nanoscopic advance of colossal significance January 27th, 2023

UC Irvine researchers decipher atomic-scale imperfections in lithium-ion batteries: Team used super high-resolution microscopy enhanced by deep machine learning January 27th, 2023

Chip Technology

Manufacturing advances bring material back in vogue January 20th, 2023

Vertical electrochemical transistor pushes wearable electronics forward: Biomedical sensing is one application of efficient, low-cost transistors January 20th, 2023

Towards highly conducting molecular materials with a partially oxidized organic neutral molecule: In an unprecedented feat, researchers from Japan develop an organic, air-stable, highly conducting neutral molecular crystal with unique electronic properties January 20th, 2023

Approaching the terahertz regime: Room temperature quantum magnets switch states trillions of times per second January 20th, 2023

Nanomedicine

One of the causes of aggressive liver cancer discovered: a 'molecular staple' that helps repair broken: DNA Researchers describe a new DNA repair mechanism that hinders cancer treatment January 27th, 2023

New nanoparticles deliver therapy brain-wide, edit Alzheimer’s gene in mice: UW researchers have found a way to move gene therapies through the blood-brain barrier, a crucial step for brain-wide CRISPR treatments of disorders like Alzheimer's and Parkinson's disease January 20th, 2023

Team undertakes study of two-dimensional transition metal chalcogenides Important biomedical application, including biosensing December 9th, 2022

SLAC/Stanford researchers discover how a nano-chamber in the cell directs protein folding: The results challenge a 70-year-old theory of how proteins fold in our cells and have profound implications for treating diseases linked to protein misfolding December 9th, 2022

Sensors

Quantum sensors see Weyl photocurrents flow: Boston College-led team develops new quantum sensor technique to image and understand the origin of photocurrent flow in Weyl semimetals January 27th, 2023

Department of Energy announces $9.1 million for research on quantum information science and nuclear physics: Projects span the development of quantum computing, algorithms, simulators, superconducting qubits, and quantum sensors for advancing nuclear physics January 27th, 2023

Development of bio-friendly transparent temperature sensor technology that precisely measures temperature changes by light January 6th, 2023

Ultrathin vanadium oxychloride demonstrates strong optical anisotropic properties Two-dimensional material could make novel strain sensors, photodetectors and other nanodevices a reality January 6th, 2023

Discoveries

One of the causes of aggressive liver cancer discovered: a 'molecular staple' that helps repair broken: DNA Researchers describe a new DNA repair mechanism that hinders cancer treatment January 27th, 2023

Stability of perovskite solar cells reaches next milestone January 27th, 2023

Qubits on strong stimulants: Researchers find ways to improve the storage time of quantum information in a spin rich material January 27th, 2023

Temperature-sensing building material changes color to save energy January 27th, 2023

Announcements

UCF researcher receives Samsung International Global Research Outreach Award: The award from the multinational electronics corporation will fund the development of infrared night vision and thermal sensing camera technology for cell phones and consumer electronics January 27th, 2023

Temperature-sensing building material changes color to save energy January 27th, 2023

Quantum sensors see Weyl photocurrents flow: Boston College-led team develops new quantum sensor technique to image and understand the origin of photocurrent flow in Weyl semimetals January 27th, 2023

Department of Energy announces $9.1 million for research on quantum information science and nuclear physics: Projects span the development of quantum computing, algorithms, simulators, superconducting qubits, and quantum sensors for advancing nuclear physics January 27th, 2023

Nanobiotechnology

One of the causes of aggressive liver cancer discovered: a 'molecular staple' that helps repair broken: DNA Researchers describe a new DNA repair mechanism that hinders cancer treatment January 27th, 2023

New nanoparticles deliver therapy brain-wide, edit Alzheimer’s gene in mice: UW researchers have found a way to move gene therapies through the blood-brain barrier, a crucial step for brain-wide CRISPR treatments of disorders like Alzheimer's and Parkinson's disease January 20th, 2023

Team undertakes study of two-dimensional transition metal chalcogenides Important biomedical application, including biosensing December 9th, 2022

SLAC/Stanford researchers discover how a nano-chamber in the cell directs protein folding: The results challenge a 70-year-old theory of how proteins fold in our cells and have profound implications for treating diseases linked to protein misfolding December 9th, 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