Flexible strain sensors: from devices to array integration

Flexible strain sensors in various device structures and materials have been extensively studied. While most of research work focusing on single sensors for strain force detection at discrete points, flexible sensor arrays for large area conformal coverage to measure the strain force distribution are urged in many application scenarios. To build a sensor array from single strain sensor devices, stretchable interconnects and reliable interfaces among the interconnects and the sensitive regions need to be developed in conjunction with the large area processing techniques. For cost-effective large area manufacturing and convenience of adopting new recipes of sensitive materials, various solution printing processes are preferred. In this paper, device design and performance optimization of the flexible strain sensors for the figure-of-merits at different aspects are firstly introduced. The processing challenges and latest progresses on the flexible strain sensor array are then described in details. Finally, the demonstrated prototype using flexible strain sensor arrays for bendable interactive interface is introduced as one example of the potential applications.