Integrated Knitted Microstructured Flexible Capacitive Sensors for Elderly Fall Detection

Abstract

This review discusses knitted microstructured flexible capacitive sensors for elderly fall detection, focusing on plantar pressure monitoring. These sensors offer stretchability, breathability, and seamless garment integration, making them ideal for wearable applications. The sensing mechanism involves multiscale deformation, including micro-protrusion contact, dielectric compression, and air-gap modulation, enhancing sensitivity (up to 8.697 kPa⁻¹ at <4.5 kPa) and broad pressure detection ranges (0–3900 kPa). Innovations in macrostructural design, such as gradient dielectric layers and double-layer spacer knits, improve linearity and adaptability to heterogeneous plantar pressure distributions. Microstructural interface designs extend dynamic range and signal fidelity. Strategies such as interlocked knitted architectures and integrated fabrication techniques address challenges like interfacial slippage and signal drift. This work benchmarks over 20 sensor configurations and presents design guidelines for high-performance wearable systems in fall detection and gait analysis.