AgNPs/TPU flexible piezoresistive sensor with multilevel biomimetic microstructures inspired by dermal papillary layer for wearable applications

Hovel screen–templated electrospinning method inspired by human dermal structure is proposed for flexible pressure sensors. • Electric–field–guided deposition and stress–localization/contact–area evolution sensing model were revealed. • The sensor achieves high sensitivity (54.44 kPa −1 ) and a broad detection range (0∼120 kPa). Flexible piezoresistive sensors are promising for wearable electronics and health monitoring, yet their advancement is often hindered by complex fabrication and limited structural tunability. Inspired by human skin dermal papillae, a silver nanoparticle/thermoplastic polyurethane (AgNPs/TPU) flexible piezoresistive sensor (ATFPS) with multilevel biomimetic microstructures is developed via screen–templated electrospinning and in situ silver nanoparticle reduction. Silver trifluoroacetate (C 2 AgF 3 O 2 ) is incorporated into the TPU solution, allowing uniform formation of AgNPs within the nanofibrous film. This approach yields a porous connective architecture reminiscent of the dermal papilla layer and establishes a three–dimensional conductive network analogous to skin neural terminals. A dermal papilla–like microprotrusion array is precisely patterned on the nanofibrous surface through electric–field–induced assembly at screen mesh template intersections. The formation mechanism of the microprotrusions and the sensing behavior of the AgNPs/TPU nanofibrous film (ATNF) are systematically analyzed via finite element modeling. Owing to its hierarchical structure, the sensor exhibits high sensitivity (54.44 kPa −1 over 0∼13.6 kPa) and a broad detection range up to 120 kPa, a response time of 360 ms, and stable performance over 1000 loading-unloading cycles. The ATFPS demonstrates excellent performance in human motion monitoring and signal transmission, providing a versatile strategy to enhance the functionality of flexible pressure sensors with significant theoretical and practical implications. Download: Download high-res image (284KB) Download: Download full-size image