Soft and stretchable liquid metal transmission lines as distributed probes of multimodal deformations

Mechanical sensing represents a key functionality in soft electronics for applications in health monitoring, human–machine interaction, or soft robotics. Current approaches typically rely on intricate networks of sensors specific to one type of deformation and one point in space, severely limiting sensing capabilities. Here, we reconcile the concept of transmission line-based multimodal distributed sensing with the field of soft and stretchable electronics. We demonstrate the scalable fabrication of microstructured elastomeric fibers integrating tens of liquid metal conductors, with the length and the cross-sectional integrity necessary to successfully apply time-domain reflectometry. The materials’ dynamic responsiveness drastically enhances collected signals compared to conventional transmission line probes, and enables the accurate detection of the mode, magnitude, and position of several simultaneous pressing and stretching events. Integrated within a large textile, an individual soft transmission line, interfaced through a single port, can decipher convoluted mechanical stimulation, bringing a new paradigm to advanced sensing in functional textiles and robotic skins.