On-CMOS High-Throughput Multi-Modal Amperometric DNA Analysis with Distributed Thermal Regulation

TL;DR

This paper presents a CMOS-based multi-modal amperometric DNA analysis platform with integrated distributed temperature regulation, enabling precise control and high throughput for various electrochemical methods.

Contribution

It introduces a 9x6 cell array with in-cell heating, sensing, and mixed-signal PID control, supporting multiple DNA analysis modes in a compact, low-power CMOS chip.

Findings

Achieved temperature regulation within +/-0.5°C accuracy.

Demonstrated successful operation of CPA, CV, IS, and temperature control modes.

Fabricated a 0.13um CMOS prototype with 0.06mm2 per channel, consuming 42μW.

Abstract

Accurate temperature regulation is critical for amperometric DNA analysis to achieve high fidelity, reliability, and throughput. In this work, a 9x6 cell array of mixed-signal CMOS distributed temperature regulators for on-CMOS multi-modal amperometric DNA analysis is presented. Three DNA analysis methods are supported, including constant potential amperometry (CPA), cyclic voltammetry (CV), and impedance spectroscopy (IS). In-cell heating and temperature sensing elements are implemented in standard CMOS technology without post-processing. Using proportional-integral-derivative (PID) control, the local temperature can be regulated to within +/-0.5C of any desired value between 20C and 90C. The two computationally intensive operations in the PID algorithm, multiplication, and subtraction, are performed by an in-cell dual-slope multiplying ADC in the mixed-signal domain, resulting in a small area and low power consumption. Over 95% of the circuit blocks are synergistically shared among the four operating modes, including CPA, CV, IS, and the proposed temperature regulation mode. A 3mmx3mm CMOS prototype fabricated in a 0.13um CMOS technology has been fully experimentally characterized. Each channel occupies an area of 0.06mm2 and consumes 42uW from a 1.2V supply. The proposed distributed temperature regulation design and the mixed-signal PID implementation can be applied to a wide range of sensory and other applications.