小型化土壤微生物燃料电池电信号放大电路的设计与运行

Design and Operation of Amplification Circuit for Electrical Signals Generated by Small-scale Soil Microbial Fuel Cells

为了提高对小型化的土壤微生物燃料电池(microbial fuel cells,MFCs)产电信号的检测能力,构建了采用加Cu^(2+)处理土壤进行产电的小型化单室MFCs,并设计和制作了基于集成运算的信号放大器,设计放大倍数100倍。将信号放大器与MFCs连接后,采用数据采集卡连续记录土壤产电的原始电压以及放大后的电压。结果显示,土壤产电电压在4 mV附近波动,而放大后的电压升至400 mV左右。统计显示原始电压与放大后的电压相关性达到极显著水平(P<0.001)。同时还发现,并非每个电压数值都严格放大100倍,而是倍率存在5%的误差,原因主要在于集成运算放大芯片存在失调误差和温度漂移误差。本研究为实现小型化MFCs产电信号的检测提供了依据。

A small-scale microbial fuel cells （MFCs） using Cu2＋ spiked soil was constructed and connected with an integrated operational amplifiers designed and produced with a designed amplification of 100 times to improve the ability to detect the electrical signal generated, then a data collector was used to recorded both the original and amplified voltage data generated by soil. The results showed that the original voltage data fluctuated around 4 mV and the amplified voltage data around 400 mV. The statistical analysis revealed that the correlation reached an extremely significant level between the original and amplified voltage data （P〈0.001）. It is noticeable that not all of the original data were amplified by 100 times strictly, instead there was a 5% error, which was attributed to the offset error and temperature drift error of the integrated operational chips. This study provided a reference in detecting electrical signals generated by small scale MFCs.