Flexible Hybrid Electronic Material Systems with Programmable Strain Sensing Architectures

Flexible hybrid electronics empower innovative electrical performance capabilities by maintaining electrical conductivity while undergoing large strains. Soft elastomeric material systems are also of great interest for means to control mechanical properties in ways unachievable by bulk materials. This work uncovers the synergy of flexible hybrid electronics and elastomeric material system concepts that becomes manifest by a strategic integration. Conductive silver microflake ink is applied to an elastomeric matrix composed with geometries that tune local strain distributions via microscopic geometries. The selection of internal beam geometries and placement of conductive ink traces are found to govern the strain transfer to the ink and hence the variation of electrical conductivity. Finite element simulations and experiments confirm the relationship between local constituent stretch and the overall material system conductivity. This relationship is exploited via two embodiments that have significant strain-sensitivity or strain-insensitivity. An extension of the concept reveals how both strain sensitivity and insensitivity may be leveraged by a single multifunctional, conductive material system. These results may motivate future concepts for strain sensors, shock isolators, biological monitoring equipment, and more.