Full Color Tactile Sensor by Using Upconversion Nanoparticle Embedded Microarray

Abstract

Rare-earth-doped upconversion nanoparticles (UCNP) release a visible ranged luminescence property under exposed near-infrared (NIR) light by multiphoton excitation. These particles are highly photochemical stability, absence of background autofluorescence, and showing various colors through one kind of light source. Therefore, UCNP have been studied extensively for applications such as a photodynamic therapy, bioimagings, and a luminescence display. In this work, we rationally utilized the unique properties of UCNP and report a new type of colorimetric tactile sensor using lanthanide doped upconverting nanoparticles. We fabricated full color array using lithography technique and applied this array into the NIR based sensor to recognize the direction and magnitude of applied pressure.