The exhaust from motorcycles is one the major source causing air pollution in Taiwan. However, the motorcycle is very popular due to its convenience and compact size. Thus, more strict regulation is needed to control the exhaust of the motorcycles. The closed-loop engine management system (EMS) may be the best solution to control the exhaust of motorcycles effectively. The oxygen sensor is the key component in the closed-loop EMS. To use oxygen sensor in motorcycles, more strict requirements are needed because motorcycles use much smaller engine, turn on/off frequently, provide limited space. In other words, a more efficient oxygen sensor is needed in a motorcycle. In this study, a thin-film type oxygen sensor was developed using advanced nanotechnology. A zirconia thin film was deposited on a porous substrate using electrophoretic deposition method. After sintering at 1400℃, a gas-tight film was obtained. The resistance from the thin-film zirconia is significantly lower than that of 1mm thick zirconia. Also, mesoporous zirconia powder with very high surface area was developed using self-assembly surfactant as a template. The specific surface area can reach as high as 50 m2/g. The electrochemical test was conducted on EPD deposited thin film cell. One side of the cell was exposed to air. The other side of cell was exposed to hydrogen-containing atmosphere or air alternatively. Consequently, the maximum voltage obtained was 0.86 V and the lowest voltage obtained was 0.04 V. These results show that the zirconia thin film is fully densified and completely covered the substrate. Thus, EPD process is a feasible technology to enhance the performance of oxygen sensor that may be used in motorcycles.

EPD, YSZ, mesoporous, oxygen gas sensor