(October 10, 2014) Device is used
to monitor brain pressure in lab mice as prelude to possible use with human
patients; future applications of this pressure-sensing technology could lead to
touch-sensitive “skin” for prosthetic devices.
Stanford engineers have invented
a wireless pressure sensor that has already been used to measure brain pressure
in lab mice with brain injuries.
The underlying technology has
such broad potential that it could one day be used to create skin-like
materials that can sense pressure, leading to prosthetic devices with the
electronic equivalent of a sense of touch.
A nine-member research team led
by Chemical Engineering Professor Zhenan Bao detailed two medical applications
of this technology in Nature Communications.
In one simple demonstration they
used this wireless pressure sensor to read a team member’s pulse without
touching him.
In a more complex application,
they used this wireless device to monitor the pressure inside the skull of a
lab mouse, an achievement that could one day lead to better ways to treat human
brain injuries.
Bao’s wireless sensor is made by
placing a thin layer of specially designed rubber between two strips of copper.
The copper strips act like radio antennas. The rubber serves as an insulator.
The technology involves beaming
radio waves at this simple antenna-and-rubber sandwich. When the device comes
under pressure, the copper antennas squeeze the rubber insulator and move
infinitesimally closer together.
That tiny change in proximity
alters the electrical characteristics of the device. Radio waves reflected by
these antennas slow down in terms of frequency. When pressure is relaxed, the
copper antennas move apart and the radio waves accelerate in frequency.