Micro-electro-mechanical system (MEMS) gripper for biomedical applications

Abstract

In recent years, the vast potential for MEMS devices in the biomedical industry has been recognised. Recent developments in MEMS technologies have made such devices attractive for use in applications involving precision engineering and scalability. It has been determined that, among their many plausible functions, their use may also extend to single human red blood cell diagnostics, whereby biomarkers of quantifiable magnitudes may be detected. Undoubtedly, the mechanical and thermal specifications by which potential devices must be able to function are very strict. In this work, a list of specifications for potential MEMS devices to be used in submerged, biomedical cell manipulation activities is laid out. Such applications include micron size, temperature sensitive test samples suspended in aqueous solutions. The MEMS devices must therefore be capable of producing enough physical displacement to apply the required strains while maintaining near-ambient temperatures at the test location while submerged in a fluid. State-of-the-art numerical modelling methodologies capable of accurately predicting MEMS device performance in a diversity of media including aqueous ones are developed and subsequently validated experimentally. The modelling methods provide MEMS design engineers with a reliable tool to be used in design and development stages and help avoid total reliability on experimental testing. In this work, seven novel devices are designed, developed and manufactured using the SOIMUMPs™ micromanufacturing process. All devices are designed to operate in air, deionised (DI) water, and 0.9 wt% NaCl solution, and their performance assessed extensively through modelling and experimental testing campaigns. The mechanical performance of the different devices when fully submerged in all media is hereby discussed. Almost all the devices are confirmed to be suitable candidates for biomedical applications. This work has demonstrated that these novel micro-actuators are promising candidates for such applications. Shortcomings have been encountered, and a plan for rectification as well as future work is presented.