Multi-Dimensionally\nFunctionalized Pressure Sensor\nfor Human Motion Detection Based on 1D AgNWs/2D rGO-Coated 3D Porous\nSponge

This study presents a conductive-type pressure sensor\nbased on\na conductive composite of 1D/2D nanomaterials coated onto a 3D nonconductive\npolymer structure with various pores. A 3D porous elastomer for the\nsubstrate was fabricated by using a sugar template, which led to an\nincreased mechanical deformation range. The sugar template enhanced\nthe surface roughness of the polymer, resulting in an improvement\nin the adhesion of nanomaterials to the polymer surface. Subsequently,\nit was functionalized by coating with hybrid nanomaterials of 1D silver\nnanowires (AgNWs) and 2D reduced graphene oxide (rGO) through a dip-coating\nprocess. When pressure is applied, the rGO/AgNWs/ecoflex pressure\nsensor deforms along the direction of the applied force, causing the\nconductive multidimensional nanomaterials to come into contact. Consequently,\nthe improved networks between the two nanomaterials expanded the current\npaths, increasing the current detected through the electrodes attached\nto the sensor. The rGO/AgNWs/ecoflex pressure sensor, with its porous\nstructure within the flexible ecoflex, demonstrated a high sensitivity\n(up to 2.29 kPa<sup>–1</sup>) over a wide detection range of\n0–120 kPa. This enables the monitoring of a wide range of motions,\nincluding small pressures such as subtle touch, respiratory vibrations,\nand drinking, as well as large pressures such as human bodily movements,\nfinger/arm bending, and foot pressure, making it an excellent candidate\nfor applications requiring precise pressure detection.