June 20, 2012      

SynTouch is the start-up company now marketing a robot finger that can sense textures more accurately than the average human.

Applications of the BioTac robot finger are endless, as soft-fingered robots with intelligent sensory capabilities are highly desirable in the medical, consumer and industrial robot markets.

As our own Dan Kara has pointed out, intelligent soft materials robots are key to the future of the industry if today?s metal robotic housekeepers and industrial arms are ever to work side-by-side with humans.

BioTac is the brain child of Professor Gerald E. Loeb and his colleagues in the Department of Biomedical Engineering at the University of Southern California.

The fluid-filled finger tip is the same size as a human finger. It also has its own ?fingerprint??made up of grooves in its artificial skin?that pick up vibrations from interacting with different textures in the same way that a human being does.

The most complex part of BioTac?s sensory process is how it interprets its touch. Loeb and his team have broken the finger?s functions down to mimic the essential components of human touch:

  • The robot is programmed with an algorithm that chooses which exploratory movement will allow it to most accurately identify the texture at hand. With its five exploratory moves, the robot finger has been able to identify 117 common materials with 95 percent accuracy.
  • Vibration sensing: A hydrophone (a microphone designed for use underwater) resides within the mechanical finger?s liquid core and picks up the vibrational patters created by the finger sliding over a particular texture. The vibrations are carried through the BioTac fluid to a pressure transducer.
  • Force sensing: BioTac has a an array of electrodes that interpret force by detecting how the external object deforms the skin and fluid path around them.
  • Thermal sensing: A thermistor is used to heat the finger above ambient temperature, similar to the biological finger. When the cooler skin is pushed against its warmer core the finger can determine patterns dependent on the heat capacity and conductivity of the object it touches.

Currently, SynTouch is focused on the use of BioTac in conjunction with prosthetic devices. A more sensory intelligent prosthesis will return another level of functionality to those missing limbs.

A paper detailing the BioTac robot finger and Loeb?s findings, entitled ?Bayesian Exploration For Intelligent Identification of Textures,? was published yesterday in Frontiers in Neurobiotics.