The Research Of Microfluidic Electrical Measurement And Energy Transformation

The technology of microfluidic chip has been being gained world-wide interests of sciences and applications. Here, a native method is set up for making such a device and two pieces of researech work are also conducted on this technology, numerically and experimentally in part: measurement on cell volume and fuel cell. Based on Coulter count princinple, a numerical prediction is conducted on microfluidic module for measuring cell volume. In the calculation, the effects on measurement are considerd, such as cell location, cell size, non-uniform electrical field through cell shapes, sizes of channel, configurations of electrodes.A fuel cell is an electrochemical device where the chemical energy in fuel and oxidant is released and transferred into electricity. Based on microfluidics, the laminar in fluid flow is used to separate the fuel and oxidant and the " internal circuit of electricity" is carried out by ion diffusion across the laminar flow of fuel and oxidant. According to the microfluidic characteristics, the electrochemical reaction is proposed to occur largely on the surface of an electrode , instead of bulky one as usual. That is, the extra area in a porous electrode contributes little to its electrochemical reaction or the j-V curve. For the case of the acid / oxygen, we simulate the membraneless fuel cell, and the results show that the performance of microfluidic fuel cells depends greatly on the fluid flow: With the increasement of volume flow rate, the boudary layer of concentration near an eletrode become thinner and thinner, and the densities of current and power increase. In this case, the cathode activity is poor , so the battery's performance is sensitive to the oxygen concentration near the cathode, while the formic acid near the anode has little effect on it.