The ability for a mechanical device to understand tactile sensations and process reactions accordingly has long been a goal of medical researchers. Recently, a team from the University of Houston was able to realize this goal with the use of a stretchable material that can be used with robotic hands to sense the difference between hot and cold water, as well as other sensations.
The new material is being referred to as an artificial skin with stretchable electronics. In addition to more lifelike prosthetics, the team led by mechanical engineering professor Cunjiang Yu feels their new advancement could serve a number of biomedical applications. And outside of the medical field, this new stretchable electronic skin could be used for creating wearable electronics and human-machine interfaces (HMIs).
The key was creating a rubber composite semiconductor that would allow the electronic components to continue working even as the material was stretched over the robotic appendage. Traditionally, semiconductors are brittle, making their use in flexible environments challenging without complex mechanical support. In addition to gauging temperature, the rubber semiconductor allowed the new "skin" to understand computer signals sent to the hand, and translate them via American Sign Language.
The skin is comprised of a silicon-based polymer called polydimethylsiloxane (PDMS). The composition of PDMS was crucial for accurately placing and holding numerous nanowires. These nanowires transport the electric current used to generate the robotic hand's ability to feel and respond.