Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Stanford develops wireless sensors that stick to the skin to track our health

16.08.2019

Skin-hugging sensors track health indicators and use a novel type of RFID to beam signals to receivers clipped to clothing

We tend to take our skin's protective function for granted, ignoring its other roles in signaling subtleties like a fluttering heart or a flush of embarrassment.


Using metallic ink, researchers screen-print an antenna and sensor onto a stretchable sticker designed to adhere to skin and track pulse and other health indicators, and beam these readings to a receiver on a person's clothing.

Credit: Bao lab

Now, Stanford engineers have developed a way to detect physiological signals emanating from the skin with sensors that stick like band-aids and beam wireless readings to a receiver clipped onto clothing.

To demonstrate this wearable technology, the researchers stuck sensors to the wrist and abdomen of one test subject to monitor the person's pulse and respiration by detecting how their skin stretched and contracted with each heartbeat or breath. Likewise, stickers on the person's elbows and knees tracked arm and leg motions by gauging the minute tightening or relaxation of the skin each time the corresponding muscle flexed.

Zhenan Bao, the chemical engineering professor whose lab described the system in an Aug. 15 article in Nature Electronics, thinks this wearable technology, which they call BodyNet, will first be used in medical settings such as monitoring patients with sleep disorders or heart conditions. Her lab is already trying to develop new stickers to sense sweat and other secretions to track variables such as body temperature and stress. Her ultimate goal is to create an array of wireless sensors that stick to the skin and work in conjunction with smart clothing to more accurately track a wider variety of health indicators than the smart phones or watches consumers use today.

"We think one day it will be possible to create a full-body skin-sensor array to collect physiological data without interfering with a person's normal behavior," said Bao, who is also the K.K. Lee Professor in the School of Engineering.

Stretchable, comfortable, functional

Postdoctoral scholars Simiao Niu and Naoji Matsuhisa led the 14-person team that spent three years designing the sensors. Their goal was to develop a technology that would be comfortable to wear and have no batteries or rigid circuits to prevent the stickers from stretching and contracting with the skin.

Their eventual design met these parameters with a variation of the RFID - radiofrequency identification - technology used to control keyless entry to locked rooms. When a person holds an ID card up to an RFID receiver, an antenna in the ID card harvests a tiny bit of RFID energy from the receiver and uses this to generate a code that it then beams back to the receiver.

The BodyNet sticker is similar to the ID card: It has an antenna that harvests a bit of the incoming RFID energy from a receiver on the clothing to power its sensors. It then takes readings from the skin and beams them back to the nearby receiver.

But to make the wireless sticker work, the researchers had to create an antenna that could stretch and bend like skin. They did this by screen-printing metallic ink on a rubber sticker. However, whenever the antenna bent or stretched, those movements made its signal too weak and unstable to be useful.

To get around this problem, the Stanford researchers developed a new type of RFID system that could beam strong and accurate signals to the receiver despite constant fluctuations. The battery-powered receiver then uses Bluetooth to periodically upload data from the stickers to a smartphone, computer or other permanent storage system.

The initial version of the stickers relied on tiny motion sensors to take respiration and pulse readings. The researchers are now studying how to integrate sweat, temperature and other sensors into their antenna systems.

To move their technology beyond clinical applications and into consumer-friendly devices, the researchers need to overcome another challenge - keeping the sensor and receiver close to each other. In their experiments, the researchers clipped a receiver on clothing just above each sensor. One-to-one pairings of sensors and receivers would be fine in medical monitoring, but to create a BodyNet that someone could wear while exercising, antennas would have to be woven into clothing to receive and transmit signals no matter where a person sticks a sensor.

###

Bao is also a senior fellow of the Precourt Institute for Energy, a member of Stanford Bio-X, a faculty fellow of Stanford ChEM-H, an affiliate of the Stanford Woods Institute for the Environment and a member of the Wu Tsai Neurosciences Institute. Other Stanford co-authors are Jeffrey B.-H. Tok, research scientist; Ada Poon, associate professor of electrical engineering; William Burnett, adjunct professor of mechanical engineering; postdoctoral scholars Yuanwen Jiang and Jinxing Li; graduate student Jiechen Wang; and former visiting scholar Youngjun Yun and former postdoctoral scholars Sihong Wang, Xuzhou Yan and Levent Beker. Researchers from Singapore's Nanyang Technological University also co-authored the study.

This research was supported by Samsung Electronics; the Singapore Agency for Science, Technology and Research; the Japan Society for the Promotion of Science; and the Stanford Precision Health and Integrated Diagnosis Center

Media Contact

Tom Abate
tabate@stanford.edu
650-736-2245

 @stanford

http://news.stanford.edu/

Tom Abate | EurekAlert!

More articles from Medical Engineering:

nachricht Highly sensitive sensors to measure the heart and brain activity
20.09.2019 | Christian-Albrechts-Universität zu Kiel

nachricht Motion pictures from living cells: Research team from Jena and Bielefeld improves superresolution microscopy
20.09.2019 | Leibniz-Institut für Photonische Technologien e. V.

All articles from Medical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: 'Nanochains' could increase battery capacity, cut charging time

How long the battery of your phone or computer lasts depends on how many lithium ions can be stored in the battery's negative electrode material. If the battery runs out of these ions, it can't generate an electrical current to run a device and ultimately fails.

Materials with a higher lithium ion storage capacity are either too heavy or the wrong shape to replace graphite, the electrode material currently used in...

Im Focus: Stevens team closes in on 'holy grail' of room temperature quantum computing chips

Photons interact on chip-based system with unprecedented efficiency

To process information, photons must interact. However, these tiny packets of light want nothing to do with each other, each passing by without altering the...

Im Focus: Happy hour for time-resolved crystallography

Researchers from the Department of Atomically Resolved Dynamics of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg, the University of Hamburg and the European Molecular Biology Laboratory (EMBL) outstation in the city have developed a new method to watch biomolecules at work. This method dramatically simplifies starting enzymatic reactions by mixing a cocktail of small amounts of liquids with protein crystals. Determination of the protein structures at different times after mixing can be assembled into a time-lapse sequence that shows the molecular foundations of biology.

The functions of biomolecules are determined by their motions and structural changes. Yet it is a formidable challenge to understand these dynamic motions.

Im Focus: Modular OLED light strips

At the International Symposium on Automotive Lighting 2019 (ISAL) in Darmstadt from September 23 to 25, 2019, the Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, a provider of research and development services in the field of organic electronics, will present OLED light strips of any length with additional functionalities for the first time at booth no. 37.

Almost everyone is familiar with light strips for interior design. LED strips are available by the metre in DIY stores around the corner and are just as often...

Im Focus: Tomorrow´s coolants of choice

Scientists assess the potential of magnetic-cooling materials

Later during this century, around 2060, a paradigm shift in global energy consumption is expected: we will spend more energy for cooling than for heating....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Optical Technologies: International Symposium „Future Optics“ in Hannover

19.09.2019 | Event News

Society 5.0: putting humans at the heart of digitalisation

10.09.2019 | Event News

Interspeech 2019 conference: Alexa and Siri in Graz

04.09.2019 | Event News

 
Latest News

Quality control in immune communication: Chaperones detect immature signaling molecules in the immune system

20.09.2019 | Life Sciences

Moderately Common Plants Show Highest Relative Losses

20.09.2019 | Life Sciences

The Fluid Fingerprint of Hurricanes

20.09.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>