On-chip flexible scaffold for construction of multishaped tissues

This paper presents a chip containing a flexible scaffold which facilitates the construction of tissues with different shapes. The chip, entirely made of Polydimethylsiloxane (PDMS), has 2 main components including actuator and channel layers. The actuator layer consists of a 6×6 array of membrane actuators, with round shapes. The channel layer has a single layered structure due to the simplicity in chip assembly and the ability to observe seeded cells via a microscope. The actuator array offers a flat surface, like a normal cell culture dish, in the rest state, while it temporarily offers a scaffold structure when actuators are activated. By changing the actuation pattern, formation of many scaffold structures is possible. To demonstrate the utility of this chip in biological application, a syringe pump is connected to all actuators to produced 2 different scaffolds, enabling the fabrication of multiple flat round and lattice shaped tissues. NIH3T3 cells with the amount of 5×10⁶were seeded on the scaffold and kept inside the incubator for 24 hours. The 25 round shaped tissues with an average diameter of 623.87 μm were simultaneously fabricated when a scaffold with large deformed actuators was used. The lattice shaped tissue with a line width of about 300 μm was also fabricated with a different scaffold structure which has less actuator displacement. Results suggest the potential usage of this chip for the preparation of many building units with different structures, without the necessity of making a new mold for a new tissue shape.