A Flexible Sensor That Moves With You

If you have a project in mind that requires some sort of gesture input or precise movements, it might become a nettlesome problem to tackle. Fear this obstacle no longer: a team from the Wyss Institute for Biologically Inspired Engineering at Harvard have designed a novel way to make wearable sensors that can stretch and contort with the body’s natural movements.

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.

6 thoughts on “A Flexible Sensor That Moves With You

  1. HaD says, “The way they work is ingenious.”

    Yeah right. I wonder how this “ingenious” thing works when a Smartphone radiating all sorts of nasty RF is nearby…

  2. Capacitive stretch sensors aren’t remotely as new or novel as the research team claims (the typical form is a sandwich of carbon-black doped silicone sheets with an insulating one in the middle), but props for describing a DIY-able process in detail (presumably; once someone jailbreaks the paper from the paywall). One neat trick is you can also generate power with these – they are basically a mechanically variable capacitor with a large (maybe order of magnitude) range. Biasing the capacitor with voltage in one state, then mechanically changing the capacitance changes the stored energy (e=1/2CV^2).

    Also: Looks suspiciously similar to https://www.stretchsense.com/fabric-stretch-sensor/

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