Flexible Substrate

A flexible substrate is a thin, bendable base material used in physiological sensor arrays to support and interconnect electronic components while maintaining mechanical compliance with biological tissues. It serves as the foundational layer that allows sensors to conform to curved or moving surfaces like skin, organs, or wearable devices, ensuring reliable signal acquisition without causing discomfort or interference with natural movement. This component typically integrates conductive traces, insulation layers, and sometimes embedded passive elements to facilitate electrical connectivity between multiple sensors and external processing units.

The flexible substrate operates by providing a mechanically compliant platform that maintains electrical integrity under deformation. It uses materials with low elastic modulus to bend and stretch with biological surfaces, while conductive pathways (often made of metals like copper or polymers like PEDOT:PSS) transmit signals from sensors to readout circuits. The substrate's flexibility minimizes stress concentration at the sensor-tissue interface, reducing motion artifacts and improving signal fidelity in dynamic environments. Advanced designs may incorporate strain-relief structures or anisotropic conductive adhesives to enhance durability and electrical performance during repeated flexing.