Printed Conductors and Resistive Elements in Photopolymer Systems: Percolation, Contact Resistance, Drift and Reliability

Printed conductive photopolymers are not qualified by a single resistance value. Their electrical state emerges from filler dispersion, percolation, cure and shrinkage, conductor geometry, surface condition and electrode interfaces, and it can drift under strain, temperature, humidity and repeated current or mechanical cycling. This review defines a qualification framework for conductive tracks and resistive elements produced in photopolymer systems. It separates bulk or volume conduction from contact resistance and geometry, treats percolation as a processing-dependent transition rather than a transferable filler threshold, and distinguishes intended piezoresistive response from uncontrolled drift. A non-compensatory matrix is proposed linking printability, dimensional state, electrical uniformity, interface stability, environmental conditioning and cyclic reliability. The central conclusion is that an electrically functional photopolymer element is a coupled material-process-interface device whose qualified resistance must remain inside a declared operating envelope after relevant conditioning, not merely at time zero.

ER-261 · Version 0.2.