The Electrochemical Aptamer-based (E-AB) sensors provide continuous and real-time monitoring of specific target molecules, including proteins, antibiotics, neurotransmitters, and more. Due to the cost-effectiveness compared to enzyme sensing assays, E-AB platforms hold significant promise for point-of-care devices and precision medicine. However, sensitivity remains a challenge, particularly in the complicated environment, such as blood and serum. While research has achieved a noise level in the picoampere range, enhancing sensitivity is crucial for detecting trace amounts of certain...
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...
Endoscopic ultrasound imaging systems require compact, low-power probes with a dense array of sensing elements. At the same time, the cabling inside the probe tube that interfaces with the external processing unit should be minimal. State-of-the-art ultrasound imagers that utilize CMUTs and PMUTs require integrating each transducer’s power-hungry analog frontend on probe, making it more difficult to satisfy the safe power limit. To address this, we propose the use of silicon microring resonators (MRRs) as ultrasound sensors. Their small element size (10-20 µm in diameter) allows us to...
The parametric amplifier is a crucial electronic device in cryogenic signal amplification, finding applications across various scientific and engineering domains, particularly in quantum computing. Unlike conventional amplifiers that rely on active components like transistors, parametric amplifiers utilize the properties of nonlinear passive devices to achieve signal amplification. Over the past decade, superconducting parametric amplifiers have become the primary system type in parametric amplification research. Leveraging Josephson Junction nonlinearity, these devices can amplify weak...
Ya-Chen (Justine) Tsai is now a first year PhD student in EECS Department, UC Berkeley. She received her B.S. in National Taiwan University, Department of Electrical Engineering in 2023. Her research interest focuses on CMOS-based microsystems for biosensing, especially the application catered to electrochemical aptamer-based sensing.
