A general 1-D model was presented to predict the characteristics of CMOS thermoresistive micro calorimetric flow (TMCF) sensor with two types of packaging, i.e., open-space type and channel type, for both gases and liquids. The 1-D model was first validated by a numerical computational fluid dynamics (CFD) model and was subsequently normalized for different fluids flow. Notably, the model proposed by Nguyen and Dötzel is a special case of our 1-D model. The normalized output of TMCF sensor is a function of normalized input parameters of Reynolds number Re and Prandtl number Pr. The scaling analysis of the sensor output, sensitivity, and power consumption was performed to optimize the design of TMCF sensors in terms of key design parameters, including the thin film thickness, the height of bottom cavity, and so on. Accordingly, three pairs of TMCF sensors were designed and fabricated by using a 0.35 μm 2P4M CMOS microelectromechanical systems technology. The fabricated sensors showed a normalized sensitivity of 230 mV/(m/s)/mW for nitrogen gas flow, which was two orders of magnitude higher than the previous CMOS flow sensors. Therefore, the proposed 1-D model is a promising tool for the sensor's system-level design with the on-chip microelectronics for the Internet of Things.

Phages based electrochemical sensors have received much attention due to their high specificity, sensitivity and simplicity. Phages or bacteriophages provide natural affinity to their host bacteria cells and can serve as the recognition element for electrochemical sensors. It can also act as a tool for bacteria infection and lysis followed by detection of the released cell contents, such as enzymes and ions. In addition, possible detection of the other desired targets, such as antibodies have been demonstrated with phage display techniques. In this paper, the recent development of phage-based electrochemical sensors has been reviewed in terms of the different immobilization protocols and electrochemical detection techniques.

In this paper, by using 0.35 μm 2P4M CMOS MEMS technology, a Thermoresistive Micro Calorimetric Flow (TMCF) sensor with two packaging designs were systematically investigated: Open-space (O-Type) and Probe-with-channel (P-Type) designs. In comparison with the O-Type design, the P-Type sensor showed an 80% enhanced sensitivity with a relieved tilt angle effect on the mainstream airflow detection. Accordingly, the P-Type packaged flow sensor for HVAC gained a prominent normalized sensitivity (S*) of 228 μV/(m/s)/mW, while also having a low power consumption (P) of less than 4.2 mW. Moreover, within the linear range of -2 to 2 m/s, an accuracy of ±0.05 m/s was achieved, thus enabling this robust flow sensor (repeatability < 0.2%) for indoor airflow measurements even in a variable ambient environment. Furthermore, the proposed P-Type TMCF sensor and its wireless multi-sensor module were applied for the development of personalized ventilation (PV) and the monitoring of predicted mean vote (PMV), both of which confirm the functionality of the developed sensor for indoor airflow measurements in the HVAC system.