Sensitive Prosthetic Arms
From: NASA Tech Briefs Insider - 12/04/2007

Advances in limb prostheses have not obscured the fact that these devices
still lack a sense of touch. Now, scientists from Northwestern University in
Chicago have shown that transplanting the nerves from an amputated hand to
the chest allows patients to feel hand sensation there. The findings could
pave the way toward prosthetic arms with sensors on the fingers that will
transfer tactile information from the device to the chest, making the wearer
feel as though he or she has a real hand.  

Earlier this year, Northwestern researcher Todd Kuiken and his colleagues at
the Rehabilitation Institute of Chicago showed that a similar
nerve-transplant approach could be used to intuitively control a prosthetic
arm. In the new study, the researchers took the nerves that would normally
carry sensory messages from the hand to the brain and implanted them into a
patch of skin on the patient's chest. After allowing the nerves to grow for
several months, Kuiken and his colleagues tested the sensory abilities of two
amputees.  

While both patients could tell the difference between different grades of
sandpaper rubbed against their skin, they each developed varying senses of
touch. One developed a broad sense of touch with sensation perceptions
triggered in three fingers at the same time. The other felt sensation in
different fingers linked to specific spots on her chest. The researchers are
now developing new components to add to prosthetic arms that will allow them
to sense the environment and transfer those signals to the wearer's chest. 

Redirection of cutaneous sensation from the hand to the chest skin of human
  amputees with targeted reinnervation
http://www.pnas.org/cgi/content/abstract/0706525104v1

Todd Kuiken
http://www.smpp.northwestern.edu/Kuiken.htm
http://www.ric.org/aboutus/people/doctors/results.aspx?doctorID=43

Building the Bionic Man
http://poptech.org/kuiken/