New smart fabric can inflate and deflate based on temperature

Researchers from the Wyss Institute have developed a new smart fabric that can inflate and deflate based on temperature-dependent liquid-vapor phase changes. The researchers believe that the new smart fabric could be used to create soft robots using a specially engineered fabric to help with rehabilitation therapies or as enhancements to protect the wearer while performing strenuous tasks.The team also believes that the smart fabric can be used in non-wearable, but independently functioning devices. Those include devices such as textile-based soft robots to help tissues like muscles and activating nerve fibers repair damage or prevent damage to them in the first place. To prevent damage, the soft robots could apply physical forces at the right frequency and precise location of the body.

Typically soft robots are pneumatically actuated, requiring a compressor to modulate air pressure inside along with bulky tubing. The Smart Thermally Actuating Textiles or STATs can induce pressure changes by electrically controlling liquid-vapor phase change in the textile. That eliminates the need for pneumatic tethers and opens new textile robotic applications.

Researchers say that their goal was to engineer robotic fabrics that can electronically sense and actuate using integrated closed-loop feedback control to self regulate. The material also had to be manufactured in arbitrary shapes and in large batches. STATs can support all those features and are lightweight and unobtrusive.

STATs are manufactured as tightly sealed pouches using commercially available woven textile membrane coated with a layer of heat-sealable thermoplastic polyurethane that incorporates embedded electrically active components. The team dynamically powers electronic components inside the STATs using an engineering fluid known as NOVEC 7000 that is vaporized by heat and expands its volume up to 100 fold allowing the robotic textile to increase and decrease internal pressure over a significant range. The devices can generate peak pressures of around 75 kPa at room temperature.