Scientists in the United States have developed new fingertips that could give prosthetic hands greater sensitivity, even allowing them to react “instinctively” to objects slipping from their grasp.The research team, which plans to present a prototype of the finger at the BioRob conference in Scottsdale, Arizona, next month, indicated that the gel-filled fingertips could give prosthetic hands greater sensitivity.Existing bionic hands do not have the reflex mechanism, so their operators have to consciously estimate the required force.“It’s very mentally taxing,” says Jeremy Fishel, a member of the team that built the new fingertip at the University of Southern California, Los Angeles.The landmark development allows the prosthetic hands to react “instinctively” to objects slipping from their grasp, New Scientist online said in a report. Researchers at the University said the tip consists of a rubber skin, filled with thick silicon gel. When an object begins to slip, the vibrations in the finger’s elastic skin transmit through the silicon gel to acoustic sensors attached to a central acrylic “bone”.This provides instant feedback, telling the motors in the hand to tighten their grip until the vibrations stop. The information could be transmitted to a pressure device worn on a patch of the hand-operator’s healthy skin, helping them to “feel” what their prosthetic hand is touching.An earlier study had said that a “rewired” woman fitted with a “bionic arm”, controlled by thought, experienced sensations in her missing hand.When Claudia Mitchell, nicknamed ‘Bionic Woman’, thinks ‘Move’, her chest muscle let out tiny electrical impulses which are picked up by the robotic arm. These signals are interpreted by a computer and motors cause the arm to move almost instantly.
