Flexible Sensors Make Robot Skin
From: Technology Research News - 09/29/2004
By: Eric Smalley

Recreating the pressure sensitivity of skin for robots and other objects is
the goal of a University of Tokyo research project using pressure sensor
arrays that can be widely distributed due to their fabrication from cheap
organic or polymer transistors on a flexible material. Potential applications
of the technology suggested by University of Tokyo electrical engineering
professor Takao Someya include pressure carpets that can identify people,
in-vehicle systems for monitoring motorists' mental and physical health, and
an artificial epidermis to facilitate more sensitive interaction between
robots and their environments. The researchers have developed a prototype
eight-centimeter-square sheet comprised of a 32 by 32 array of organic
pressure sensors supporting a density of 16 sensors for every square
centimeter. Conductive graphite particles in the prototype's
pressure-sensitive rubber layer cause its electrical resistance to shift in
response to pressure, while the layer and a copper electrode are enameled to
an array of organic transistors. Only one transistor operates for each
activated sensor thanks to an active matrix design, making the array less
power-consumptive than a simpler array in which sensors are wired into a
grid. The active-matrix control scheme makes the arrays intelligent enough to
permit individual sensors at specific feedback points to check the heartbeat
and respiration rate of collapsed hospital patients, for example, enabling
the skin to determine whether the patient is simply resting or is in trouble,
according to Someya. Organic transistors' inexpensiveness can offset their
increased size and slower performance compared to silicon transistors. Someya
expects electronic skin to be ready for practical applications in about half
a decade. 

http://www.trnmag.com/Stories/2004/092204/Flexible_sensors_make_robot_skin%20_092204.html

