Development and Assessment of Highly Sensitive, Economically Viable, and Environmentally Sustainable Fabric-Based Flexible Capacitive Pressure Sensors

Flexible capacitive pressure sensors offer unparalleled benefits—malleability, stability, simplicity, low power consumption, and minimal sensitivity to temperature fluctuations. Yet, their expensive materials, complex, and environmentally detrimental manufacturing processes impede their widespread adoption. This study unveils a cost-effective, simple, and environmentally sustainable method to fabricate highly sensitive flexible capacitive pressure sensors that outperform costly sensors manufactured using unsustainable materials. By sandwiching a flexible polyurethane (PU) sheet between two silver-metallized fabrics (SMF) and securing them with polyethylene adhesive tape (PAT), we have eliminated the need for expensive and specialized equipment and methods. Crafting sensors of varying dimensions is now as simple as cutting fabric and PU sheets with everyday tools. The key to the sensor's performance lies in the exceptional deformability of the PU layer under applied pressure, resulting in an impressive sensitivity of 0.377358 kPa⁻¹.This surpasses the sensitivity of existing non-eco-friendly and expensive sensors reported in the literature. Additionally, the sensor exhibits excellent pressure resolution and high repeatability. Our sensor accurately detects intricate human movements like palm bends and taps, showcasing its potential across diverse applications—from robotic skins to smart wearables and seamless human-computer interactions. With a production cost as low as 0.34 USD per sensor —significantly lower than the costs of sensors reported in the literature—this study signals a significant advancement in flexible sensor technology, combining affordability, simplicity and sustainability with exceptional performance.