A microscale mechanical stimulator for generating identical in-plane surface strains toward live cells on multiple loading sites

To investigate complicated mechanobiological events at the cellular level, microdevices that are capable of delivering controlled and identical mechanical signals to multiple loading sites are of imperative need. Although current devices in this field can generate identical loads under static conditions, parallel delivery of dynamic loads with identical loading parameters often requires the use of a multi-channel pump or multiple pumps to avoid the differential patterns of load magnitudes caused by the compliant fluidic channels. This however increases the complexity of the devices and somewhat compromises the miniaturization nature. In this study, we design and fabricate a bi-layered microfluidic device driven by a single external pump that can simultaneously deliver identical strain profiles to all the loading membranes (each with 500 μm in diameter). The loading performances under both static and cyclic loading conditions were experimentally examined. The influences of the total membrane number and the loading frequency were also examined. By minimizing the number of external pumping units for parallel operation, this device allows further miniaturization of on-chip mechanical stimulators for various studies in the field of cellular mechanobiology.