Flexible Sensing Technology for Myocardial Tissue Contractile Force With Integrated Magnetically Actuated Mechanical Stimulation.

The myocardial organ-on-a-chip platform represents a transformative approach for replicating cardiac physiological functions in vitro, with significant potential for drug screening and disease modeling applications. Dynamic mechanical stimulation enhances both structural and functional maturation of cardiac tissues, leading to improved contractile performance, while real-time contractility monitoring provides essential data for investigating cardiac disease mechanisms and evaluating pharmacological interventions. However, integrating mechanically stimulated mature myocardial tissue cultures with real-time detection of weak contractile activity remains challenging. Here, an integrated platform that combines programmable mechanical stimulation with real-time contractile force monitoring was developed. The system employs aligned fiber scaffolds to guide three-dimensional (3D) cardiac tissue formation. Meanwhile, a wireless tunable magnetic actuation unit applying physiological relevant mechanical stimulation was employed demonstrating remarkable efficacy in enhancing sarcomeric structure (42.9% increase in sarcomere length, from 1.42 to 2.10 µm) and contractile function (47.5% increase in force amplitude, from 19.47 to 28.72 µN). An embedded flexible sensor based on liquid metal for real-time monitoring of contraction force was introduced, achieved a minimum detectable force of 1.52 µN. The system addresses current limitations in cardiac tissue engineering where stimulation and sensing platforms are typically separate, integrating both dynamic maturation enhancement and continuous contractile performance monitoring.