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

在小规模上设计微结构可能会带来许多挑战。其中一个挑战是以最低成本复制小规模设计的能力。尽管规模很小，但最具限制性的因素是成本。对于大学和个人来说，使用设备可能是一笔巨大的支出，但它们引发的调查有朝一日可能会改变世界。这种微型研究使用的是生物兼容的微型机器人，可用于药物输送或微创手术。拥有合适的微型机器人系统的微结构可以帮助确定微型机器人何时以及如何在体内执行特定的任务。在韩国大田韩国先进科学技术研究所(KAIST)国家纳米制造中心(NNFC)主任池元安博士的协助下，能够完成能够重复制造复杂微结构的生物芯片工厂的生产。当涉及到微型机器人在体内的具体应用时，生物相容性是一个非常令人关注的组成部分，因为这种基于多糖基的水凝胶是一个有趣的研究点。为了制备多糖基水凝胶，海藻酸钠和氯化钙的交联化过程是通过液滴产生的方法完成的，该方法还可以包裹有机和非有机材料。正是由于这种能力，这些水凝胶被称为人造细胞。由顺磁性纳米颗粒包裹的人造细胞可以在均匀磁场的全局输入下移动。使用一种名为对象粒子计算的算法方法，这些人造细胞在全局输入磁场下移动，直到它们到达障碍物。然后，人造细胞从障碍物沿顺时针方向移动，重复这种模式。这个过程一直持续到人造细胞到达它们的最终目的地并退出算法。为了生产该算法，使用了由光刻和软光刻技术生产的PDMS模具。控制流量是一个气动阀门系统，它将控制流体流量以及新藻酸盐细胞的输入到算法中。总而言之，该系统被称为芯片上的生物工厂，它可以连续生产在对象粒子计算中设计的微结构。在NNFC安？S博士团队的协助下，完成制造过程所需的设备和专业知识随时可用。这种芯片上的生物工厂将使复杂微结构的可重复制造方法具有成本效益。该奖项根据东亚和太平洋夏季学院计划，支持一名美国研究生的暑期研究，由NSF和韩国国家研究基金会联合资助。

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.