The way they work is ingenious. Layers of silicone are sandwiched between two lengths of silver-plated conductive fabric forming — by some approximation — a capacitance sensor. While the total surface area doesn’t change when the sensor is stretched — how capacitance sensors normally work — it does bring the two layers of fabric closer together, changing the capacitance of the band in a proportional and measurable way, with the silicone pulling the sensor back into its original shape as tension relaxes. Wires can be attached to each end of the band with adhesive and a square of thermal film, making an ideal sensor to detect the subtlest of muscle movements.
With this method, customized sensors can be laser cut from larger mats with ease. Applications in fitness training, exoskeletons, robots, smart wearables, artificial muscles, healthcare devices, and more, abound. The team has generously provided a guide on how to make these sensors if you want to experiment with them yourself!
Via The Wyss Institute.