Development of 3D-printed flexible devices for strain sensing and damage detection

Advances in wearable electronics and soft electronics have led to the development of novel manufacturing techniques for electronic circuitry. This work utilizes the unique properties of flexible printed devices for strain sensing and damage detection. Inks made from Thermoplastic Polyurethane (TPU) and a mix of different solvents are used for insulation and adhesion to the monitored structure. Silver particles are added to the ink for conductivity. A robotic arm controlled by customized printing programs delivers high resolution prints directly onto the structures for testing. Finally, carbon-fiber-reinforced thermoplastic-matrix Open Hole Tension (OHT) coupons are subjected to tensile loading and the strain sensing and damage-detection capabilities are demonstrated.