用于细胞外电信号测量的CMOS集成生物传感芯片的研究

新型的细胞外电信号传感芯片是采用0.6 μm标准CMOS工艺设计制造,片上集成了6×6单元有源传感阵列、模拟多路选择器、输出缓冲器、参考源和数字控制电路.有源传感单元面积为60μm×60μm,包含15μm×15μm的传感电极和预处理电路,能够线性放大幅值范围100μV～25 mV的微小信号,电压增益为40dB.并采用相关二次采样工作模式降低固定模式噪声,提高传感器的精度.在标准CMOS工艺基础上,应用无电浸镀金改进传感电极的生物兼容性,并采用特殊封装技术提高芯片在溶液环境中的稳定性.溶液中模拟生物信号测量验证了该芯片的功能.

Research of CMOS Integrated Biosensor for ExtracellularBioelectrical Signal Recording

A new CMOS (complementary metal oxide silicon) biosensor chip designed for recording electrophysiological activities of in-vitro cultured cells is reported. It is designed and fabricated in a standard 0.6μm CMOS process, consisting of 6×6 active sensor array, analog multiplexer, output buffers, reference sources and digital controlling circuit. Each sensor cell is 60μm× 60μm in the dimension, including a 15μm×15μm electrode and a pre-processing circuit which could linearly amplify signals with peak-to-peak values from 100μV to 25 mV. The correlated double sampling circuit is utilized to remove the common-mode noise. Post-CMOS processes including electroless gold plating and special package technique are implemented to enhance the biocompatibility and stability of the biosensor. The tests carried out in the solution have verified the electrical functionality of the biosensor chip.