SeLf-powered self-rEshaping Autarkic skin For wireless motes - LEAF

ongoing

We will combine 3D reshaping, energy harvesting, and energy storage within a single, thin foil. The thin foil of several micrometer thickness is going to be fabricated by inkjet and capillary printing on a temporal carrier support and consists of an adhesion sacrificial layer (own technology relying on lanthanum acrylic acid coordination polymer) and a strain inducing bilayer made of hydrogel and a stiffening layer (own innovation technology). The combination of specifically designed bilayer polymer system (polyethylene alt maleic anhydride type hydrogel and polyimide materials) is able to reshape into Swiss-roll architectures with few hundreds of micrometer diameter through a selective etching of the sacrificial layer and swelling of the hydrogel in a water-based solution. We will implement high precision capillary printing (HPCAP) to print dedicated structures with high control over length, thickness and separation with (sub-)micrometer resolution and high reproducibility of a variety of materials, which deliver different functionality. Self-powering of the autonomous device is ensured through the use of bi-functional materials deposited into interdigitated micro-electrode structures, function as light converter and storage materials at the same time. The thus created photo-storage microscale supercapacitor is embedded onto the thin foil and will serve as autonomous power source for the integrated silicon chip. The 2D area of the ultrathin foil delivers maximized surface area of the interdigitated finger structure and ensures sufficient light absorption to power the integrated RFIC (e.g. an active tag/sensory system). The optimized weight (R ~ 0.95) will be granted by the ultrathin nature of the foil (around 5um), while mechanical stability of the final device is ensured through 2D-to-3D reshaping. Key feature of our final device is the ability to retain its functionality also after 3D reshaping and its deployment onto the application surface.