Electric Skin that Rivals the Real Thing From: Technology Review - 09/13/2010 By: Katherine Bourzac Flexible sensors could give prosthetics and robots a more sensitive sense of touch. The tactile sensitivity of human skin is hard to re-create, especially over large, flexible surfaces. But two California research groups have made pressure-sensing devices that significantly advance the state of the art. Highly sensitive surfaces could help robots pick up delicate objects without breaking them, give prosthetics a sense of touch, and give surgeons finer control over tools used for minimally invasive surgery. "Our goal is to mimic the human skin," says Zhenan Bao, professor of chemical engineering at Stanford. Human skin responds quickly to pressure and can detect objects as small as a grain of sand and light as an insect. --- Two separate research groups have developed pressure-sensing devices that can match human skin in sensitivity and flexibility. Stanford University researchers created a system based on organic electronics that is 1,000 times more sensitive than human skin. The Stanford system consists of a clear silicon-containing polymer called PDMS. The team designed PDMS with arrays of micropillars that stand up from the touchable surface, which enables the material to flex quickly and return to its original shape. Meanwhile, University of California, Berkeley researchers built low-power tactile sensors based on arrays of inorganic nanowire transistors. The transistors are connected to a layer of conductive rubber made of carbon nanoparticles that can detect changes in the material's electrical resistance. "The nanowires are being used as active electronics to run the tactile sensor on top," says Berkeley professor Ali Javey. The Stanford system requires about 20 volts to operate, while the Berkeley device needs less than five volts. The new electronic-skin devices "are a considerable advance in the state of the art in terms of power consumption and sensitivity," says Trinity College at the University of Dublin professor John Boland. Read the entire article at: http://www.technologyreview.com/computing/26256/page1/ Stanford researchers' new high-sensitivity electronic skin can feel a fly's footsteps http://news.stanford.edu/news/2010/september/sensitive-artificial-skin-091210.html Zhenan Bao http://baogroup.stanford.edu/zbao Bao Research Group http://baogroup.stanford.edu/index.php Takao Someya http://www.ncrc.iis.u-tokyo.ac.jp/e/someya.html Ali Javey http://www.eecs.berkeley.edu/Faculty/Homepages/javey.html http://www.technologyreview.com/tr35/profile.aspx?trid=784 Matei Ciocarlie http://www.willowgarage.com/pages/people/matei-ciocarlie-research-scientist Highly sensitive flexible pressure sensors with microstructured rubber dielectric layers http://www.nature.com/nmat/journal/vaop/ncurrent/full/nmat2834.html Nanowire active-matrix circuitry for low-voltage macroscale artificial skin http://www.nature.com/nmat/journal/vaop/ncurrent/full/nmat2835.html Flexible electronics: Within touch of artificial skin http://www.nature.com/nmat/journal/vaop/ncurrent/full/nmat2861.html Submitted by Jerry Weisman