Self-folding Microgrippers and Their Applications as BioMEM Systems

microgrippers;self-actuation;single cell analysis;biopsy;bioMEMs;Chemical & Biomolecular Engineering

Polat, BerilGracias, David H. ;

Johns Hopkins University

关键词: microgrippers;    self-actuation;    single cell analysis;    biopsy;    bioMEMs;    Chemical & Biomolecular Engineering;   

Others  :  https://jscholarship.library.jhu.edu/bitstream/handle/1774.2/59363/POLAT-THESIS-2016.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: JOHNS HOPKINS DSpace Repository

【 摘 要 】

Self-actuating microtools have evolved to be more efficient as diagnostic biological microelectromechanical (bioMEM) systems because of their miniature and robust designs. One of these microtool designs, namely microgrippers, is fabricated and used with the purpose of single cancer cell and tumor lesion diagnostics. They are self-actuated tools that can be used tethered or untethered with many potential applications in the field of medicine. Self-folding microgrippers have different applications depending to their dimensions and designs. We utilized single cell microgrippers as micro-arrayed diagnosis tools by capturing mammalian cells in vitro without causing any damage. Since the microgripper design allows for nutrients in the environment to diffuse in and out of the cell between the gripper arms, the cells stay viable over 24 hours, which facilitates dynamic observations on the cells. We successfully detected specific molecules in a captured cell using surface-enhanced Raman spectroscopy (SERS). Additionally, thermally-responsive untethered grippers can be used as soft tissue sampling tools with high resolution compared to conventional biopsy forceps. The addition of a thin nickel film on the gripper arms provides better motion control in vivo and thus, better coverage of the sampling area. Although the efficiency of these grippers was proven in a statistical model, we designed an in vivo statistical sampling study to support this model. Finally, we implemented a biocompatible actuation mechanism, capable of keeping the gripper arms open until reaching a tissue wall. Potential applications of microgrippers are extensive. Depending on their dimension, design, and the fabrication materials used, it is possible to adapt them into any desired application. Therefore, they are one of the pioneer designs in microtool systems in medicine. In this thesis, I aim to give a review of different microgripper designs from other research teams and explain our design and its applications.