Fixation of engineered skeletal muscle fiber using magnetically induced mechanical interlocking for micro mechanical structures

Engineering skeletal muscle fibers are expected to be used as bio-actuators because they bring various advantages of biological materials to actuators, such as the ability to operate at much smaller sizes. However, to prevent muscle fibers from malfunctioning due to spontaneous shrinkage during culture, fixation during the culture process is necessary. Furthermore, to prevent muscle fibers from breaking during fixation and considering the load reduction for bio-actuators, this study combines our previously proposed method of creating magnetic ends at both ends of muscle fibers, and uses magnets to attract the magnetic ends to achieve fixation on 3D-printed fixation parts based on mechanical interlocking. By using measurement system consists of electrical slider and strain gauge, tensile test was applied to the muscle fiber fixed on 3D printed fixation part. We found that magnetic ends remained fixation on fixation part even muscle fiber was stretched to break, with a maximum tensile force $600 \mu \mathrm{~N}$.