“Researchers have demonstrated “giant flexoelectricity” in soft elastomers that could improve robot movement range and make self-powered pacemakers a real possibility. In a paper published this month in the Proceedings of the National Academy of Sciences, scientists from the University of Houston and Air Force Research Laboratory explain how to engineer ostensibly ordinary substances like silicone rubber into an electric powerhouse,” reports ScienceDaily.com.
Animal muscles act as an energy converter, contracting when they receive an electrical current form a nerve ending. Transducers are devices that generate electrical current when they are bent, or subject to heat or vibration. “This is called piezoelectricity and is useful in creating sensors and laser electronics.” Unfortunately, aside from animal muscle, “…these naturally occurring materials are rare and consist of stiff crystalline structures that are often toxic to humans.”
“In a paper published this month in the Proceedings of the National Academy of Sciences, Kosar Mozaffari, graduate student at the Cullen College of Engineering at the University of Houston; Pradeep Sharma, M.D. Anderson Chair Professor & Department Chair of Mechanical Engineering at the University of Houston and Matthew Grasinger, LUCI Postdoctoral Fellow at the Air Force Research Laboratory, offer a solution. ‘This theory engineers a connection between electricity and mechanical motion in soft rubber-like materials,’ said Sharma. ‘While some polymers are weakly piezoelectric, there are no really soft rubber like materials that are piezoelectric.'”
“The term for these multifunctional soft elastomers with increased capability is “giant flexoelectricity.” In other words, these scientists demonstrate how to boost flexoelectric performance in soft materials.” If flexoelectric materials become strong enough, it would theoretically be possible to build robots modeled after Mammalian anatomy, with the flexoelectric material taking the place of Mammalian muscles.”
“The mechanics of soft elastomers generating and being manipulated by electrical signals replicates a similar function observed in human ears. Sounds hit the ear drum that then vibrates and send electrical signals to the brain, which interprets them. In this case, movement can manipulate soft elastomers and generate electricity to power a device on its own. This process of self-generating power by movement appears as a step up from a typical battery.” The robotic equivalent of a knee or ankle joint could become a source of piezoelectric power, so that vibrations from taking a robotic step could help to recharge the robot and prolong it’s battery life.