Instrumented rubber insole for plantar pressure sensing

Abstract We demonstrate a printed pressure sensor embedded rubber insole for measurement and analysis of plantar pressure. Unlike the conventional mode of pressure sensing of interdigitated capacitors in which change in dimension of electrodes by external pressure leads to variation of capacitance, for this study, the change in capacitance is entirely led by variation of relative permittivity of the surrounding dielectric medium with applied pressure. The measured sensitivity of the sensor is 4.3 V/MPa and shows high linearity in the pressure exerted by human weight. The plantar pressure is detected with locally embedded sensors to register various foot postures at three high-pressure regions: hind-foot, mid-foot, and fore-foot.

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