EAPSI: Fabrication of Complex Microstructures Using Global Inputs on Biofactory-On-A-Chip

Sheckman Samuel I, Holland PA

Investigators

Abstract

Designing microstructures on the small scale can provide a number of challenges. One such challenge is the ability to reproduce a small scale design for minimal costs. As interesting as the small scale can be, the most limiting factor is cost. Equipment usage can be great expenditure for universities and individuals, but the investigations they lead to can one day change the world. Such investigations in the microscale is using biocompatible microrobots that can be used for drug delivery or minimally invasive surgery. Having the right microstructure of the microrobotic system can help determine when and how microrobots perform specific tasks within the body. With the assistance of Dr. Chi Won Ahn, Director at the National Nano Fabrication Center (NNFC), located at the Korean Advanced Institute of Science and Technology (KAIST) in Daejeon, South Korea; the production of a biofactory-on-a-chip capable of the repeatable fabrication of complex microstructures can be completed. Biocompatibility is a component of large concern when it comes to the topic of microrobots for the specific use of in vivo applications, as such polysaccharide-base hydrogels are an interesting point of research. To create polysaccharide-base hydrogels, the process of cross-linking sodium alginate and calcium chloride is completed through a droplet producing method, which can also encapsulate organic and nonorganic materials. It is because of this ability that these hydrogels are referred to as artificial cells. Artificial cells encapsulated by paramagnetic nanoparticles can be manipulated to move under global inputs of a uniform magnetic field. Using an algorithmic method call, object particle computation, these artificial cells are moved under the globally input magnetic field until they reach an obstacle. From the obstacle, the artificial cells then move in a clockwise direction and the pattern is repeated. The process continues until the artificial cells reach their final destination and exits the algorithm. To produce the algorithm, a PDMS mold, produced from photolithography and softlithography techniques are used. Controlling the flow is a pneumatic valve system which would control the fluid flow as well as the input of new alginate cells into the algorithm. Altogether, the system is called a biofactory-on-a-chip, which can continually produce microstructures designed in the object particle computation. With the assistance of Dr. Ahn?s team at the NNFC, the equipment and expertise necessary to complete the manufacturing process is readily available. Such a biofactory-on-a-chip will enable the repeatable cost-effective fabrication method of complex microstructures. This award, under the East Asia and Pacific Summer Institutes program, supports summer research by a U.S. graduate student and is jointly funded by NSF and the National Research Foundation of Korea.