New Approaches for Soft, Stretchable, and Biomimetic Electronics

Michael Dickey
North Carolina State University
Wednesday, February 22, 2012
Duke University, 115 Teer | 12:00pm

This talk will describe efforts in our research group to create and study electronic devices with new properties and architectures by harnessing interfacial phenomena, microfabrication, and the unique properties of a moldable liquid metal.  Conventional electronics are typically fabricated from rigid materials (e.g., silicon for transistors, copper for antennas). New materials are being explored as candidates for flexible / stretchable / soft electronics because of the novel applications that emerge from their mechanical properties.  Examples include flexible displays, implantable devices, electronic textiles, and soft robots.  This talk with discuss the underlying fundamental science motivating active areas of research in our group:

  • Ultra-stretchable wires, sensors, antennas, and microelectrodes created by injecting a gallium-based metal alloy into elastomeric microchannels.  The metal is a liquid at room-temperature with low-viscosity (water-like) and can be micromolded due to a thin, oxide skin that forms rapidly on its surface.  The properties of the metal will be discussed as well as methods to shape the metal to form ultra-stretchable electronic components.  
  • Soft, biomimetic memory (“memristor-like”) devices composed of hydrogels and moldable metal.  These memory devices are composed entirely of soft materials and operate based on the ability to control the thickness of an interfacial oxide between the metal and gel.   This system is brain-like in the sense that it is soft, 3-D, operates in an aqueous environment using ionic conductance, and has characteristics that mimic synapse formation.
  • Self-folding polymer sheets that fold in response to exposure to light.  Two-dimensional patterning techniques are inexpensive and abundant.  Examples include inkjet printing, screen printing, and photolithography (used to make electronics).   Our approach converts these 2D patterns into 3D shapes within seconds in a hands free manner using pre-stressed polymer films, which may be useful for actuation, assembly, and packaging.