A One-Step-Packaged CMOS /Microfluidics Wireless Bio-Analyzer for Point-of-Care Diagnostics Yan-Ting Hsiao , Ya-Chen Tsai , Wei Foo , Hung-Yu Hou, Yun-Chun Su , Shu-Yan Chuang, and Jun-Chau Chien

Abstract

Point-of-care (POC) diagnostics can revolutionize current medicine by enabling rapid, at-home molecular testing for early disease detection and treatment monitoring. Though several mainstream POC technologies exist, such as paper-based lateral flow assays (LFAs) and microfluidic cartridges, they either lack quantification capability or require a dedicated reader for electrical readout. Miniaturization enabled by high-performance CMOS integrated circuits (ICs) has been proposed to address these limitations, but complex CMOS /microfluidics packaging due to the need for electrical connections remains a significant challenge. In this work, we present a fully wireless solution based on near-field inductive coupling. By enabling wireless power and data communication through a 1.5-mm on-chip coil operating at 700 MHz, the CMOS chip can be seamlessly embedded into standard microfluidics fabrication flows. The proposed CMOS bio-analyzer supports electrochemical, pH, and temperature sensing. The electrochemical front end performs highly sensitive readout from immunosensors, while the pH and temperature sensors are used to mitigate environmental e ffects. Implemented in TSMC 180-nm CMOS technology, the system consumes 2 mA from a rectified 2.5-V supply. The electrochemical sensor employs a fully differential capacitive transimpedance amplifier (TIA) and achieves 0.24-pArms input-referred current noise and 128.8 dB of extended dynamic range. Immunosensing of C-reactive protein (CRP) and a prototype