Heart disease remains a leading cause of global mortality,
underscoring
the need for advanced technologies to study cardiovascular diseases
and develop effective treatments. We introduce an innovative interferometric
biosensor for high-sensitivity and label-free recording of human induced
pluripotent stem cell (hiPSC) cardiomyocyte contraction in
vitro. Using an optical cavity, our device captures interference
patterns caused by the contraction-induced displacement of a thin
flexible membrane. First, we demonstrate the capability to quantify
spontaneous contractions and discriminate between contraction and
relaxation phases. We calculate a contraction-induced vertical membrane
displacement close to 40 nm, which implies a traction stress of 34
± 4 mN/mm2. Finally, we investigate the effects of
a drug compound on contractility amplitude, revealing a significant
reduction in contractile forces. The label-free and high-throughput
nature of our biosensor may enhance drug screening processes and drug
development for cardiac treatments. Our interferometric biosensor
offers a novel approach for noninvasive and real-time assessment of
cardiomyocyte contraction.