VTEC MEMS flow sensor
This micro sensor chips for water flow monitoring are micro fabricated by the state-of-the-art MEMS technologies. The sensing principle is based on the pressure measurement with Wheatstone bridge gold metal strain gauges, which guarantee high signal-to-noise ratio. The diaphragm is made of special material, which is resistant against water and moisture with high robustness and reliability. Small size, low cost, high sensitivity and easy packaging characteristics make this innovative MEMS flow sensor more suitable for wide and high-volume applications. It could be used in the application of water flow monitoring, water pipe leakage monitoring, water flow measurement at household level, etc.
Figure 1: MEMS flow sensor. An array of MEMS sensor chips distributed along the main pipe which can provide a full profile of water flow (or pressure).
VTEC Photonic Crystal Sensor This photonic crystal sensor is developed based on the state-of-the-art fiber sensing applications that rely on micro- and nano fabrication of devices at the end of the fiber. It is extremely tiny, 20µm wide and 220 nm thick. The principle to use this as a water flow sensor is based on the relationship between temperature and flow. Water flowing has a cooling effect on the membrane. And the temperature is measured by measuring the wavelength shifts of two different cavity resonance modes generated by the photonic crystal membrane. The main feature of this sensor is high sensitivity, fast recovery, low cost and tiny size which is suitable for simultaneous accurate measurement and for mass production.
Figure 2： Photonic crystal sensor. A photonic crystal membrane is on an optical fiber tip. The PhC membrane is 4.5 times smaller than a normal hair.