INTEGRATED FULL-BRIDGE STRAIN SENSOR ON A POLYMER CANTILEVER FOR PRECISE CARDIOMYOCYTE CONTRACTION FORCE MEASUREMENT

Cardiotoxicity caused by drugs is of greater concern because it not only affects heart function by changing cardiomyocyte properties, but also directly affects human life.Currently available methods for evaluating cardiotoxic effects have limitations in accuracy and sensitivity, which has spurred the search for alternative approaches.Recent advances emphasize the importance of measuring variables like cardiomyocyte contractility and the speed of calcium ion movement, in addition to traditional electrophysiological methods.Our study introduces a novel polymer cantilever equipped with a full-bridge strain sensor for assessing cardiomyocyte contractility with enhanced sensitivity.This sensor uses polyimide (PI, KMSF 1000), with a Young's modulus lower than that of SU-8, to increase the sensitivity of the strain integrated on the cantilever surface.Experimental results indicate that the full-bridge configuration of the strain sensor increases sensitivity by up to twofold compared to the half-bridge configuration.Additionally, a PI thin layer used as a protective layer doubles the detection sensitivity relative to an SU-8 thin layer.Our experimental results demonstrate that this novel cantilever can be effectively used for cell culture and as a drug screening platform.