Jun-Chau Chien (Advisor)

Cell deformability is a label-free biomarker with great potential for studying various cellular processes and disease states. This mechanical property provides insights into changes in the cytoskeleton, nuclear structure, and overall cell state, demonstrating significant clinical potential in cancer research, immune responses, and stem cell sorting.

The current state-of-the-art method for detecting cell deformability combines inertial microfluidics for precise cell positioning with an ultra-high-speed camera to capture the degree of cell deformation under strong fluidic pressure...

We present the integration of CMOS-embedded subtractive microfluidics with single-photon avalanche diode (SPAD) fluorescence lifetime sensors, enabling independent channel addressability for parallel readout. Microfluidic channels are realized by selectively wet-etching the back-end-of-line (BEOL) metal routing above the SPAD sensors, reducing the analyte-to-active-region spacing to 7 μm while allowing for precision alignment. Simultaneous readout from two SPADs underneath two separate fluidic channels is demonstrated, establishing a pathway toward a scalable, multiplexed lab-on-CMOS...

We have previously demonstrated electrochemical circuits for measuring the concentration of various biomolecules and drugs using structure-switching aptamers. Structure-switching aptamers are single-stranded nucleic acids that can be sequenced to exhibit conformational changes when bound to specific biomolecules. By conjugating aptamers with a redox reporter, voltammetry or amperometry-based measurements can be applied and signals in the nano to pico-amp scale can be captured using transimpedance amplifiers (TIA). Because the signals of interest are very small, noise-cancellation...

Nanostructured materials have become an exciting area of research for the improvement of traditional electronic sensors. The high surface area to volume ratio of nanoflowers, nano-urchins, and nanoporous materials has allowed them to exhibit significant improvements in limit of detection and sensitivity compared to analogous planar sensors. These complex structures have also demonstrated the capability of improving biofouling resistance in complex media by helping to screen fouling agents from the active surface. Despite these advantages, moving this material beyond the laboratory has...