Preparation and Performance Study of Piezoelectric Shoes Based on Shrapnel Transducer Structure

Abstract

In recent years, piezoelectric shoes have been shown in numerous studies to have the potential to power built-in LED lights and foot sensors. In previous studies, the output power of piezoelectric shoes often remained around 1 mW due to the limitation of displacement. For this, this paper proposes piezoelectric shoes based on the structure of shrapnel transducer (length × width × height: 90 × 50 × 15 mm3), which consists of two piezoelectric bimorph. The energy harvesting efficiency of the shrapnel piezoelectric transducer under different excitation frequencies and displacements was tested in the laboratory. When the excitation frequency was 4 Hz and the displacement was 5 mm, the maximum output voltage was 11.03 V, the maximum output current was 0.18 mA, and the maximum output power was 2.03 mW under the matching resistance of 60 kΩ. Then, three people of different weights tested the output characteristics of piezoelectric shoes under different exercise modes. The experimental results showed that the output power increases with the wearer's weight and exercise intensity. When the body weight was 80 kg, the output powers of walking, running, and jumping were 8.24, 12.71, and 23.16 mW, respectively, and the corresponding matching resistances were 40, 14, and 12 kΩ, respectively. The shoe successfully lit up a 0.6-meter-long LED flexible light strip (35 LED lights), which could be used in future research to provide power for rechargeable luminous shoes for night workers or positioning shoes for people who are prone to getting lost.