8/14/2019 Wouldn't It Be Good When Another Pulls
1/1
Wouldn't it be good when another pulls your chestnuts out of the
fire? Or at leasta machine...a
This is what haptic technology deals with: the sense of touch,
with an array ofapplications, from telesurgery and robotic remote
control to improved immersivecomputer games. Haptic devices are now
just simple "rumble pack" games controllersand force-feedback
devices like the Phantom Desktop, a graspable pen on the tip ofa
motorized robotic arm.
A team led by Susumu Tachi at the University ofTokyo, Japan,
developed the Gravity Grabber, an improved technology
stimulatingtouch and employing a simple set up of motors and belts:
two tube-shapedattachments that match a person's thumb and
forefinger.
Each tube has two motors on top connecting it to a belt around
the tip of thefinger. The motors moves the belt inducing the
feeling of touching an object orholding something heavy by pulling
more tightly.
"Something as simple and low-cost as the Gravity Grabber could
be ideally suitedto gaming," said co-author Kouta Minamizawa.
The same team developed an even more sensitive haptic device for
remotemanipulation, named Haptic Telexistence, made of a large
mechanical controller puton an user's hand and connecting him/her
to a remote robotic "slave" hand.
Each fingertip on the robotic hand has LEDs with a small camera
behind and thelevel of reflected light from an object shows its
shape and the degree of holding.A similar force is then sent to the
user's fingertips through an array of tinypegs that pop up and
release a minuscule electric current to stimulate nervefibers.f
"This "electro-tactile feedback" is more subtle than alternative
techniques suchas vibration. This can deliver a sensation a texture
and even, in principle,heat," said co-researcher Katsunari
Sato.
Farzam Farbiz at the Agency for Science, Technology and Research
in Singapore isworking on a project involving the stimulation of
the forearm muscles withelectricity to deliver the sensation of
hitting a tennis ball. By tuning thefrequency and amplitude of
signals sent by electrodes to the arm, his deviceimitates the
muscle contractions of a real contact with the ball."The sensations
are not yet fully realistic," admitted Farbiz, who is working
onimproving the device.
A very delicate artificial touch sensor is the Fibratus Tactile
Sensor, developedby a team led by Satoshi Saga at Tohoku University
in Japan. It is made offeathers embedded in a silicone gel mounted
in a specific pattern and with a videocamera beneath. The movement
of the feathers in the gel shifts the filtered light,
a change detected by the camera. A computer determines the
pressure exerted on thefeathers.f
"This might ultimately be used to give robots a more human-like
ability to touchand feel." said Saga.
