Full color tactile sensor fabrication using upconverting nanocrystals

Abstract

Lanthanide doped upconversion nanocrystals (UCNs) release a visible ranged luminescence property under exposed near-infrared (NIR) light by multiphoton excitation. These nanocrystals are highly photochemical stability, absence of background autofluorescence, low toxicity, and large anti-Stokes that orthogonally separate excitation and emission peaks. Thus, UCNs have been studied extensively for applications such as a photodynamic therapy, bioimagings, an UCNs ink of inkjet printer for anti-counterfeit, a luminescence display. In this work, we rationally utilized the unique optical properties of UCNs and report a new type of colorimetric tactile sensor using rare-earth-doped upconverting nanocrystals We fabricated full color pixel arrays using lithography technique and applied these arrays into the NIR based sensor system to recognize the direction and magnitude of applied pressure.