Stanford engineers
have created a plastic skin that can detect how hard it is being pressed and
generate an electric signal to deliver this sensory input directly to a living
brain cell. Researchers spent a decade trying to develop a material that mimics
skin's ability to flex and heal, while also serving as the sensor net that
sends touch, temperature and pain signals to the brain. Ultimately she wants to
create a flexible electronic fabric embedded with sensors that could cover a
prosthetic limb and replicate some of skin's sensory functions.
The heart of the
technique is a two-ply plastic construct: the top layer creates a sensing
mechanism and the bottom layer acts as the circuit to transport electrical
signals and translate them into biochemical stimuli compatible with nerve
cells. The top layer in the new work featured a sensor that can detect pressure
over the same range as human skin, from a light finger tap to a firm handshake.
Researchers scattered billions of carbon nanotubes through the waffled plastic.
Putting pressure on the plastic squeezes the nanotubes closer together and
enables them to conduct electricity.
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