Electric-field Micro-Electro-Mechanical Systems (MEMS) sensors with broad bandwidth and large dynamic range are an enabling technology for real-time monitoring of fast transient overvoltage in the power grid. They significantly alter lightning damage and operation faults and therefore help establish a more secure grid. We propose a new method and architecture for electric-field sensing, which overcomes the incompatibilities between electric-field measurements of broad spectrum and large dynamic range. Scientifically, this compound structure with coupled piezoelectric effect and piezoresistive effect transduces electric field changes into resistance alterations via internal pressure. This structure has an hour-glass-shaped cavity, which contains a piezoelectric crystal and leaves the piezoresistive membrane vibrating freely. The newly proposed sensors have a broadened frequency bandwidth of up to 100 kHz and a 15-fold improved sensing magnitude. In addition, this sensor decreases cost by two orders and reduces energy consumption to 0.018%, which makes them readily implantable into electrical appliances in the power grid.

IrMn exchange-biased anisotropic magnetoresistive sensors have been optimized for increased outputs and reduced noise. An ~56% increase in peak-to-peak outputs has been achieved in IrMn exchange-biased NiFe thin-film sensors, relative to sensors without IrMn. Critically, these sensors' transfer functions show a linear and symmetric magnetic field response with small hysteresis. The tradeoff between detection range and sensitivity has also been explored, and an inverse proportional relationship is observed. In addition, sensor noise performance can be improved with an IrMn exchange bias layer and further enhanced by the addition of a thin MgO layer between the NiFe and the Ta capping layer. The decrease in magnetic 1/f noise can be attributed to magnetization stabilization by IrMn and a reduction in pinning sites by MgO. This improved performance from IrMn exchange-biased anisotropic magnetoresistive sensors renders them promising for many different applications.

A bio-inspired absolute pressure sensor network has been developed. Absolute pressure sensors, distributed on multiple silicon islands, are connected as a network by stretchable polyimide wires. This sensor network, made on a 4’’ wafer, has 77 nodes and can be mounted on various curved surfaces to cover an area up to 0.64 m × 0.64 m, which is 100 times larger than its original size. Due to Micro Electro-Mechanical system (MEMS) surface micromachining technology, ultrathin sensing nodes can be realized with thicknesses of less than 100 µm. Additionally, good linearity and high sensitivity (~14 mV/V/bar) have been achieved. Since the MEMS sensor process has also been well integrated with a flexible polymer substrate process, the entire sensor network can be fabricated in a time-efficient and cost-effective manner. Moreover, an accurate pressure contour can be obtained from the sensor network. Therefore, this absolute pressure sensor network holds significant promise for smart vehicle applications, especially for unmanned aerial vehicles.

A stand-alone stretchable absolute pressure sensing system has been proposed and demonstrated. This is the first step towards the development of an absolute pressure distribution monitoring system for industrial applications. The pressure sensing network can be fabricated in a cost-effective manner on silicon wafers and utilizes the advantages of microelectromechanical system technology. The sensor network possesses great stretchability, capable of being expanded to 10 000% times its original dimensions. Pressure sensing elements in the network have a sensitivity of about -0.14 mV/V/kPa. In addition, low-noise readout electronics, designed for signal conditioning, power management, and wireless communication, were implemented to realize the stand-alone absolute pressure sensor network. Furthermore, the stand-alone pressure sensing system prototype has been tested by measuring pressure at different locations in real time. Experimental measurements show good agreement with simulations and a commercial reference sensor. The sensor system can measure real-time mapping profiles of absolute pressure and has great potential for a variety of industrial applications.