Fabrication of patterned micromuscles with high activity for powering biohybrid microdevices

In this paper, we report a microfabrication approach to patterned three-dimensional growth of muscle cells for powering biohybrid microdevices. The microwells confined by adhesion-resistant polyethylene glycol (PEG) microstructures were patterned on SiO₂-based substrate with controllable surface topography for muscle cell culturing. The morphology and motility of neonatal rat cardiac myocytes patterned within microwells were analyzed with different topographical heights of the PEG barrier. It was found that isolated aggregates of cardiac muscles showed various beating activities depending on the morphology and the number of cells. Furthermore, three-dimensionally grown cardiac muscle cells mediated by a higher physical barrier of PEG microstructures generated higher contraction force with faster beating frequency than those of cells attached to the collagen-coated surface on the culture dish (control), suggesting that control over surface topography of microwells for cell growth would be potentially useful in engineering cell motors. Thus the technique presented here would provide a valuable platform for optimizing the activity and functions of patterned muscle cells in building up integrated bioactuated microdevices.