Nanoscale strain gauges on flexible polymer substrates.

This article focuses on the development and testing of nanoscale gold strain gauges embedded in soft polydimethylsiloxane (PDMS) polymers as a novel approach for measuring biological cell forces electrically and in real time. The study presents the design, fabrication via a sacrificial aluminum layer method, COMSOL simulations, and electrical and mechanical characterization of these strain gauges, which are capable of detecting compressive strains corresponding to forces in the nanonewton to micronewton range. While actual cell force measurements were not performed, the devices demonstrated expected electrical responses to controlled mechanical strains applied using radius of curvature fixtures, with straight nanowire designs showing higher sensitivity and fabrication yield than serpentine designs. This work suggests potential for scalable, high-throughput cell force sensing that could overcome limitations of current optical imaging methods, particularly for applications involving small cellular subpopulations such as blood platelets.