Thayer and Shashank Priya, study leaders and researchers from Virginia Tech,
have developed a robotic hand that is capable of performing human tasks such
as opening doors and typing.
robotic hand is called a dexterous anthropomorphic robotic typing hand, or DART
hand. It is designed to both look and act just like a real human hand, and
closely mimics the actions of the human hand more than any other robotic
version to date.
robotic hands created before the DART hand have had varied numbers of fingers
that did not look or act like an actual human hand. In
addition, these other robotic hands could not accurately type at the speed that
the DART hand can.
the DART hand, the Virginia Tech researchers studied the physiology of the human
hand. The human hand has 40 muscles with 23 degrees of freedom in both the
wrist and hand. By observing the hand's range of motion, grasp force and
musculoskeletal structure, Thayer and Priya were able to make servomotors and
wires imitate the human hand's actions.
total of 19 motors, researchers were able to reach 19 degrees of freedom. Rapid
prototyping was used to fabricate components, which cut weight, costs and
hand is controlled through input text by a keyboard or a voice recognition program, where individual fingers
receive commands on where to position themselves. For example, when typing, a
finger receives a command to place itself above the correct letter. The finger
presses the key, and the letter is checked for accuracy. If the letter pressed
was incorrect, the DART hand is able to twist and turn the wrist to navigate
the keyboard and press the backspace key.
greatest significance of our work is the optimization of the hand design to
reduce the number of motors in order to achieve a similar degree of freedom and
range of motion as the human hand," said Priya. "This allowed us to
achieve dimensions that are on par with the human hand. We were also able to
program the hand in such a manner that a high typing efficiency can be
hand is capable of typing 20 words per minute with just one hand on a regular
computer keyboard. Using both hands, researchers expect that the DART hands
will be able to type at least 30 words per minute. The average human types
approximately 33 words per minute.
difference between the DART hand and a human hand is that the DART hand's
fingers are controlled independently while tendons, moving joints in more than
one finger, connect human hand muscles.
have already experimented with grasping tasks," said Priya. "In the
current form it is not optimized for grasping, but in our next
version there will be enough sensors to provide feedback for controlling the
improvements that the researchers plan to apply to the DART hand are silicon
skin, tactile sensors, temperature sensors, and tension sensors.
study was published in Smart Materials and Structures.