Liwei Lin (Advisor)

This paper demonstrates, via a novel compact model and experiments, that squegging in micromechanical resonant electrical switches (resoswitches) [1] is controllable via impact electrode design. The model captures the nonlinear dynamics of impact contact and predicts squegging. Unlike other numeric and finite-element (FEM)-based models, this physical parameter-based model has no convergence difficulties when simulating impact, accurately captures squegging, and runs within any circuit simulator with up to 100× simulation time improvement compared to commercial software....

We present a surface-tension driven electrochemical liquid metal (LM) actuator without the gas-producing sidereaction and capable of fabrication/operation in ambient air for practical applications. A hybrid supercapacitor is introduced to inhibit the common counter electrode side reactions, and the use of quasi-solid-state ionic hydrogel instead of liquid electrolyte further enables non-volatile operations. A 2×4 LM droplet array is demonstrated to actuate by a low driving voltage of 3.5 V for a maximum force of ~8.5 mN and a displacement of 0.56 mm in only 1.75 s. With the favorable...

Surface tension plays an important role in miniaturized systems as the scaling law favors its relative significance over other forces such as gravity, magnetic, and structural stiffness. As such, surface tension effects have induced process issues in microfabrication such as stiction but also provided opportunities in using the surface tension to drive microdevices, such as those based on electrowetting-on-dielectric (EWOD), electrocapillary, and continuous electrowetting (CEW) mechanism, … etc. In this project, we exploit the giant outputs by the switching of surface tension...

Access to affordable and user-friendly biosensors is crucial for advancing global healthcare. While lateral flow immunoassays have been the primary solution for decades, their limited sensitivity and suboptimal sample utilization present challenges. This project represents a systematic progression towards developing economically viable biosensors with heightened sensitivity, covering a range of diseases from viral infections to cancer. By integrating nanoplasmonics to induce visually perceptible signals and harnessing the coffee ring effect for protein pre-concentration, we achieved...