Zhigang Wu of Uppsala University, in collaboration with Laird Technologies’ researchers, has devised a wireless microfluidic stretchable radio frequency electronics (µFSRFE) strain sensor that features a traditional rigid circuit board coupled with a multipurpose antenna.
The latest µFSRFE technologies have allowed the integration of inflexible electronics parts with elastomers’ channels containing fluid metal, resulting in the production of systems that can retain their initial shape even after extreme mechanical deformation. These flexible electronics can be used with any moving and bent surfaces on a robot or a human being, thereby serving as a smart e-skin for remote control and health monitoring.
The self-contained, large-area wireless sensor can send the health information straight away to a PC wirelessly. The design allows measurement of repetitive bending throughout moveable parts or a huge area remotely. The key component of the sensor is a reversibly deformable and mechanically reconfigurable patch antenna that features two layers of microfluidic channels containing liquid metal alloy in a silicone elastomer.
The elastomer-based antenna can tolerate continual mechanical stretches, while sustaining its electrical function to some level. The antenna then retains its initial form once the stress is removed. Moreover, the sensor’s electrical properties are more responsive to mechanical strains. In addition to sending and receiving radiofrequency signals similar to traditional antennas, the stretchable antenna behaves like a reversible huge-area strain sensor in the incorporated device.
The researchers assessed the electrical performance of the radiofrequency transmitter sub-module and the standalone antenna. They also developed, deployed and assessed a personal computer-assisted radiofrequency receiver for accepting and processing the measured information.
During the demonstration, the strain sensor effectively performed periodic monitoring of the repetitive motions of the human body and sent the corresponding information wirelessly to the computer-assisted receiver located at 5 m distance. The new sensor can be used for innovative applications.
The researchers have presented their findings in Advanced Functional Materials.