Axial Plane Nanoscale Measurements of Cardiomyocytes Based on Microspheres

After eons of evolution, biological systems have developed excellent actuating methodology in micro-nano scale, which inspired the design and development of advanced microrobots. Cardiomyocytes have received extensive attention following the development of bio-syncretic robots in terms of its spontaneous contraction and high energy efficiency. However, the multipoint, high-precision synchronized, and comprehensive acquisition of the axial motion parameters of cardiomyocytes still constitutes the major factor hindering the development of quantitative control methods for bio-syncretic robots. Herein, off-focus imaging method was proposed to quantify the axial beating of cardiomyocyte. The spontaneously beating of cardiomyocytes were quantitative analyzed based on the combination of cross-correlation and off-focusing imaging. We also validated the use of the proposed SiO
₂
microspheres in cardiotoxicity test. Following the administration of isoproterenol, cardiomyocytes exhibited positive inotropic and chronotropic effects. Finally, we analyzed the beating responses of individual cardiomyocytes at different locations, and we validated the feasibility of multipoint, synchronized measurements. In the future, this study can also be extended to the analysis of the motion coupling relationship between individual cardiomyocytes and cardiomyocyte clusters, thus providing a data acquisition platform for the dynamic analysis and modeling of bio-syncretic robot actuators.