Triboelectric pressure sensor using PDMS/β-Si₃N₄ micro-composite for plantar pressure detection

• Fabricated a flexible pressure sensor using pristine polydimethylsiloxane elastomer (PDMS) and β-Si 3 N 4 micro-composite. • Integration of β-Si 3 N 4 micro-composite enhance the triboelectric property for plantar pressure detection. • Promising application of the flexible pressure sensor in diagnosing plantar pathology-related diseases. The design and fabrication of flexible pressure sensors are critical for the development of portable and wearable electronic devices. In this study, a novel flexible polymer micro-composite based pressure sensor was fabricated using pristine polydimethylsiloxane elastomer (PDMS) integrated with β-Si 3 N 4 , which enhance the overall triboelectric property of the composite. The sensor consisted of a copper/PDMS+β-Si 3 N 4 /copper tri-layer structure, all encapsulated within a polypropylene sheet. The best fabricated pressure sensor (PDMS+10% β-Si 3 N 4 ) was selected based on the device performance evaluation, yielding an optimum output voltage of 4.72 V, sensitivity of 3.16 V/N with a force range of 0.15 N-5 N and power density 1.88 μW/cm² at a load resistance of 1 MΩ. Experimental results demonstrated the optimized device generated output voltages of 0.75 V, and 15.78 V for the applied forces of 0.15 N and 5 N, respectively. Furthermore, the prototype device was placed on the foot to assess pressure measurement capabilities proving effective across individuals of varying weights. The results demonstrated the promising application of the polymer micro-composite based flexible pressure sensor for diagnosing plantar pathology-related diseases.