A team of researchers has synthesized a new material that solves one of the most difficult problems in the quest to create wearable, unobtrusive sensitive sensors: the problem of pressure.
To solve this problem, the team developed a sensor that keeps working even when hugged, sat upon, leaned on, or otherwise squished by everyday interactions. The secret lies in vapor-printing clothing fabrics with piezoionic materials such as PEDOT-Cl (p-doped poly(3,4-ethylenedioxythiophene-chloride). With this method, even the smallest body movement, such as a heartbeat, leads to the redistribution of ions throughout the sensor. In other words, the fabric turns the mechanical motion of the body into an electrical signal, which can then be monitored.
Of particular advantage is that this all-fabric sensor can be worn in comfortable, loose-fitting clothing rather than embedded in tight-fitting fabrics or stuck directly onto the skin. This makes it far easier for the sensors to gather long-term data, such as heartbeats, respiration, joint movement, vocalization, step counts and grip strength — a crucial health indicator that can help clinicians track everything from bone density to depression.