Flexible, Stretchable and Self-Healable Optoelectronic Materials for Detection Avoidance and Physical Protection

Task 6 Project Activities Adaptive optoelectronic camouflage systems inspired by cephalopod skin Description Fabrication of adaptive optoelectronic camouflage systems inspired by cephalod skin Exposing a layer of polydimethylsiloxane (PDMS) to UV/ozone generates a hydroxyl terminated surface for bonding via condensation reactions with similar chemistry associated with a layer of silicon dioxide blanket deposited onto the array. The silver (Ag) and the thermochromic composite are lithographically patterned on top of the diode array. The resulting system is then peeled from the glass. Similar bonding processes enable aligned integration of a separately fabricated multiplexed array of photodetectors onto the backside of PDMS. Software development tools from LabVIEW 2012 will be used to implement the control and system operation of the sensors and actuators components. A complete system consists of 16x16 array of such unit cells, in the form of a flexible skin (1.4x1.4cm). The thin geometries of the active components and the compliance of the PDMS substrate lead to high levels of mechanical flexibility. The artificial chromatophores incorporate a thin layer of microencapsulated leucodye embedded in a photosensitive transparent polymer. The dye is based on a fluoran chemistry that reversibly converts from open (colored) to closed (colorless) from lactone rings upon temperature cycling below and above 47 °C, respectively. This composite combines abilities for color modulation via the leucodye with photopattering via the transparent polymer matrix. Outcome(s) The outcome of this task will be the fabrication of adaptive optoelectronic camouflage systems inspired by cephalopod skin.