Biomimetic micro devices for the medical and biological applications

SangHoon Lee

Dept. of Biomedical Engineering, Dankook University

Objective: Biomimetic system is the goal of science and engineering, as the natural creatures have been adapted optimally to the environment of earth for more than 3 billion years. Many researches to develop the devices mimicking the nature have been carried out, and their representatives might be the robots, bio-sensing, artificial organs, artificial membrane, and so forth. We have developed some biomimetic devices using the polymer based micro-fabrication technology, and we will introduce here biomimetic products; 1) production of curved structures like spider, 2) production of artificial egg.

Method: We have fabricated continuously the curved structures such as microfiber, microtube, and microspheres like the production of spider silk in the nature. For the continuous microfabrication, the PDMS- and the pulled micropipette-based microfluidic apparatus was employed. Into the apparatus, the polymerizable and non-polymerizable sample and sheath fluids are introduced respectively. By the micro scale phenomena, the sample fluid travels floated among the coaxial sheath fluid at the outlet channel. By the UV light exposure onto the outlet channel, the sample fluid is polymerized, and the solidified fiber moves out of the channel without touching the inner wall of outlet channel. As a second product, we will introduce the artificial eggs using microfluidic platform. For the fabrication, we introduced 3 solutions (biological material, photopolymerizable solution, and aqueous solution with PVA) into the microfluidic chip, and the egg like microcapsules are produced.

Result: Through the suggested method, the microfibers can be produced continuously, and its diameter can be easily changed by the regulation of flow rates. Similarly, the microtube and microsphere can be produced in a continuous way. We have encapsulated and cultivated yeast cells inside the microcapsule, and they survived well inside the microcapsule.

Conclusion: By employing the polymeric microfluidic platforms, we have fabricated diverse curved structures. By mixing other materials, they can have diverse functionality such as biosensing and stimuli-responsive actuating.

Key words: Biomimetic, PDMS, Microfluidic, Photopolymerization