Energy-efficient building (EEB) is becoming increasingly important in tackling energy shortage issue. However, the market adoption of EEB is hindered by the high cost of initial installation and sensors. MEMS sensors are promising for EEB because of the potential low cost and low power consumption and integration with the other functions on the same sensor chip. In this work, we design and fabricate an integrated micro hot-wire sensor using CMOS MEMS technology for the energy management and control systems of EEB. The scaling of micro flow sensors based on hot-wire anemometry using 1-D analytical model is conducted to predict the sensor output, sensitivity, scaling exponents and power consumption as functions of different dimensions and materials. Computational Fluid Dynamics (C...[ Read more ]

Energy-efficient building (EEB) is becoming increasingly important in tackling energy shortage issue. However, the market adoption of EEB is hindered by the high cost of initial installation and sensors. MEMS sensors are promising for EEB because of the potential low cost and low power consumption and integration with the other functions on the same sensor chip. In this work, we design and fabricate an integrated micro hot-wire sensor using CMOS MEMS technology for the energy management and control systems of EEB. The scaling of micro flow sensors based on hot-wire anemometry using 1-D analytical model is conducted to predict the sensor output, sensitivity, scaling exponents and power consumption as functions of different dimensions and materials. Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA) are used to verify our assumptions. A SPICE equivalent circuit model for a micro flow sensor is constructed for the system-level design of a micro flow sensor with on-chip feedback amplifier using 0.35μm CMOS MEMS technology. A post-CMOS MEMS process for a 1.5mm² sensor chip using Deep Reactive Ion Etch (DRIE) and spray coating is proposed to finish the fabrication. The fabricated flow sensor was characterized at different flow rates. The fabricated sensor with a dimension of 300μm×2μm×3.76μm demonstrated a sensitivity of 23.87 mV/(m/s) and power consumption of 0.79 mW at U_in=5m/s. The experiment results were consistent with the theoretical prediction and the best results show an average error of only 5%.