Flexible and transparent pressure sensor

January 25, 2016
The pressure sensors wrap around and conform to the shape of the fingers while still accurately measuring pressure distribution. Credit: 2016 Someya Laboratory

Healthcare practitioners may one day be able to physically screen for breast cancer using pressure-sensitive rubber gloves to detect tumors, owing to a transparent, bendable and sensitive pressure sensor newly developed by Japanese and American teams.

Conventional pressure sensors are flexible enough to fit to soft surfaces such as human skin, but they cannot measure pressure changes accurately once they are twisted or wrinkled, making them unsuitable for use on complex and moving surfaces. Additionally, it is difficult to reduce them below 100 micrometers thickness because of limitations in current production methods.

To address these issues, an international team of researchers led by Dr. Sungwon Lee and Professor Takao Someya of the University of Tokyo's Graduate School of Engineering has developed a nanofiber-type pressure sensor that can measure pressure distribution of rounded surfaces such as an inflated balloon and maintain its sensing accuracy even when bent over a radius of 80 micrometers, equivalent to just twice the width of a human hair. The sensor is roughly 8 micrometers thick and can measure the pressure in 144 locations at once.

The device demonstrated in this study consists of organic transistors, electronic switches made from carbon and oxygen based organic materials, and a pressure sensitive nanofiber structure. Carbon nanotubes and graphene were added to an elastic polymer to create nanofibers with a diameter of 300 to 700 nanometers, which were then entangled with each other to form a transparent, thin and light porous structure.

The flexible pressure sensor conforms to the shape of an inflated balloon. Even when the sensor is stretched and deformed with the shape of the balloon, the device still measures the pressure distribution accurately. Credit: 2016 Someya Laboratory

"We've also tested the performance of our with an artificial blood vessel and found that it could detect small and speed of pressure propagation," says Lee. He continues, "Flexible electronics have great potential for implantable and wearable devices. I realized that many groups are developing flexible sensors that can measure but none of them are suitable for measuring real objects since they are sensitive to distortion. That was my main motivation and I think we have proposed an effective solution to this problem."

Explore further: Revolutionary new graphene elastomer exceeds sensitivity of human skin

More information: Sungwon Lee, Amir Reuveny, Jonathan Reeder, Sunghoon Lee, Hanbit Jin, Qihan Liu, Tomoyuki Yokota, Tsuyoshi Sekitani, Takashi Isoyama, Yusuke Abe, Zhigang Suo, and Takao Someya, "A Transparent, Bending Insensitive Pressure Sensor," Nature Nanotechnology, DOI: 10.1038/nnano.2015.324

Related Stories

Gold shapes up as new-age sensor

July 7, 2014

(Phys.org) —A wearable pressure sensor that is both highly sensitive and cheap to produce could aid the development of prosthetic skin, touch-on flexible displays and energy harvesting, as well as changing the way vital ...

A printable, flexible, lightweight temperature sensor

November 9, 2015

A University of Tokyo research group has developed a flexible, lightweight sensor that responds rapidly to tiny thermal changes in the range of human body temperature. This sensor is expected to find healthcare and welfare ...

Recommended for you

Nano-decoy lures human influenza A virus to its doom

October 25, 2016

To infect its victims, influenza A heads for the lungs, where it latches onto sialic acid on the surface of cells. So researchers created the perfect decoy: A carefully constructed spherical nanoparticle coated in sialic ...

New method increases energy density in lithium batteries

October 24, 2016

Yuan Yang, assistant professor of materials science and engineering at Columbia Engineering, has developed a new method to increase the energy density of lithium (Li-ion) batteries. He has built a trilayer structure that ...

Nanofiber coating prevents infections of prosthetic joints

October 24, 2016

In a proof-of-concept study with mice, scientists at The Johns Hopkins University show that a novel coating they made with antibiotic-releasing nanofibers has the potential to better prevent at least some serious bacterial ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.