谐振式MEMS生物传感器系统检测电路设计

Detection Circuit Design of Resonant MEMS Biosensor System

文中提出了一种基于MEMS悬臂梁的生物检测系统。针对多通道MEMS悬臂梁阵列传感芯片响应迅速、灵敏度高、输出信号微弱等特点,设计了基于两级放大电路、锁相环及等精度计数的低噪声、高稳定性的信号处理与频率检测电路;构建了基于蠕动泵、气泵与MCU控制电路的微流体驱动控制系统,该系统具有体积小、精度高、功耗低等特点。测试结果表明,该生物检测系统对生物样品检测具有良好的准确性和重复性,开环测试误差小于±0.3 Hz,闭环误差小于±0.002 Hz,微流体控制精度最小可达0.247μL。

In this paper,a bio-detection system based on MEMS cantilever was presented.Since the multi-channel MEMS cantilever array sensor has the characteristics of rapid response,high sensitivity,and weak output signal,a low-noise and high-stability signal processing and frequency detection circuit was designed,which is composed of a two-stage amplifying circuit,a phase-locked loop and an equal precision counting circuit.A microfluidic drive-control system based on peristaltic pump,air pump and MCU control circuit was proposed.The system had features of small size,high precision and low power consumption.The test results show that the whole bio-detection system has good accuracy and repeatability for biological sample detection.The open-loop test error is less than±0.3 Hz,while the closed-loop error is less than±0.002 Hz,and the accuracy for control of the microfluidic is as low as 0.247μL.