Mechano-Electrophysiological Signals Measuring System Based on Cantilevered Micropipette Force Electric Sensor

Cardiomyocytes (CMs) are the contractile motors of the heart that generate the force required to pump blood into the systemic circulations. Its contractive process can be described as electrical stimulation that ultimately leads force generation (excitation-contraction coupling). Investigation of the mechanical forces and electrical signals is crucial in heart disease research and related drug assessment. Despite the long-term development of instruments for measuring mechanical or electrical signals of CMs separately, in situ synchronous measurement of these signals of CMs still faces challenges. To address this gap, in this study, we developed cantilevered micropipette force electric sensor (CMFES) to realize mechanical and electrical signal measurements. We recorded, for the first time, the synchronous local beating, ion flow-related contraction characteristics, and action potential of CMs. The results revealed that during the late stage of Na+ influx in CMs, the cells began to contract, with a time difference of approximately 100–130 ms between the action potential and the contraction peak. Furthermore, to demonstrate the accuracy and capability of the proposed methods, we utilized CMFES to perform quantitative mechanical measurements, achieve high-resistance sealing, and record ion channel currents. In summary, our approach achieved measurement accuracy comparable to that of atomic force microscopy (AFM) and patch clamp techniques, which are currently considered the most precise technologies for mechanical and electrical measurements. We believe this novel approach has broad applications in various research areas involving the intersection of biomechanics and electrophysiology.