A static characterization of stretchable 3D-printed strain sensor for restoring proprioception in amputees

The lack of proprioception in lower limb amputees is a major cause of gait asymmetry, balance issues and risk of falling. Various devices have been proposed to solve these problems, allowing to gather information about the gait cycle and provide the patient with sensory feedback. The static characterization of a novel stretchable strain sensor manufactured through 3D printing will be studied in this study. This sensor will be the sensitive element of a new wearable proprioceptive device for patients with passive lower limb prostheses. For the realization of the sensor, an elastomeric material (Agilus30Clear), printed with the PolyJet methodology, was used for the support while a eutectic Gallium-Indium (eGaIn) metal alloy was used as the deformation sensitive element. Static tests were conducted for studying the behavior of the sensor with respect to strain. The results provided a good response to the stimulus with good repeatability, sensitivity and R-2 values.