This project was a part of my Mechatronics II course project. In this project we designed a noble active knee brace that was fully flexible and was built with relatively low cost. The main part of this brace was a thick fabric with a thin elastic layer inside the middle part to increase rigidity. This brace used an Arduino Lilypad as the controller and a pair of ADXL345 accelerometers for sensing the state of leg during walking. Then, by sensing which phase of walking the leg is in currently it commands two servomotors to tighten or loosen the middle part of the brace. Most of the circuitry was woven into the fabric using conductive tread.
The whole system is powered by a 12000mAh battery using a USB cable. With each servomotor drawing no more than 150mAh, the total power consumption of the system is less than 400mAh which results in more than one-day (potentially two days of normal usage) battery life for the device.
The following video shows this brass in action:
Complete report of this project is available at the link below: