Textile-based Micro Electro Mechanical System (MEMS) Accelerometer for Pelvic Tilt Mesurement

This project proposes the application of textile-based MEMS accelerometer for measuring pelvic tilt angle. Textile-based accelerometer provides an alternative to the costly and hazardous radiographic measurement of pelvic tilt. The flexibility of textile structure makes it more advantageous to conform to body contour than rigid digital inclinometer and more accurate than indirect trigonometric measurement. Conventional MEMS devices are usually constructed from silicon-based material, which is expensive and requires access to clean room equipments. Textile material is relatively low-cost, flexible, lightweight, readily available, environmental friendly and easy to use. Silver nanoparticles (AgNPs) are used here as the transducer material to induce piezoresistive effect when stress is applied on the textile. The electrode and resistor parts of the accelerometer were made by stamping different volume of AgNPs on a cotton cloth. Starch ironing method was used to stiffen the textile. The force is applied by the 10 g mass attached at the tip of the accelerometer. The working principle of this accelerometer is based on piezoresistive effect generated by the conductive nanomaterials patterned on textile substrate. When a force is applied, the accelerometer experiences mechanical stress which causes change in its resistance. The initial resistance for the accelerometers ranges from 17.00 to 30.97 MΩ. When the tilt angle increases, the relative resistance change also increases in nearly linear behavior. The concept of textile-based accelerometer is proven feasible as there is a transducible effect of resistance change when the sample is tilted.