Tiny, Flexible Sensors Gauge Pressure

A new kind of flexible, transparent pressure sensor developed at UC Davis for use in medical applications relies on a drop of liquid, reports the university's media office.

The droplet is placed in a flexible "sandwich" of polydimethylsiloxane (PDMS). The sensor acts as a variable electrical capacitor. When the sensor is pressed down, the sensing droplet is squeezed over conductive electrodes, increasing its capacitance.

"There's a huge need for flexible sensors in biosensing," said Professor Tingrui Pan, who led the research project.

He and his colleagues used the sensor successfully in measuring pulse in the human neck. The sensor also has potential for use in "smart gloves," giving physicians an enhanced ability to measure the firmness of tissues and detect tumors, and in "smart contact lenses" to monitor intraocular pressure without affecting vision.

Pan's research paper -- for which graduate students Baoqing Nie and Siyuan Xing and ophthalmology professor James Brandt served as co-authors -- appeared in the December 2011 issue of the journal Lab on a Chip.

The National Science Foundation gave partial support to the project.