Based on the metal-oxide-semiconductor field effect transistor(MOSFET)stress sensitive phenomenon,a low power MOSFET pressure sensor is proposed.Compared with the traditional piezoresistive pressure sensor,the present pressure sensor displays high performances on sensitivity and power consumption.The sensitivity of the MOSFET sensor is raised by 87%,meanwhile the power consumption is decreased by 20%.
In recent years, flexible electronic devices have become a hot topic of scientific research. These flexible devices are the basis of flexible circuits, flexible batteries, flexible displays and electronic skins. Graphene-based materials are very promising for flexible electronic devices, due to their high mobility, high elasticity, a tunable band gap, quantum electronic transport and high mechanical strength. In this article, we review the recent progress of the fabrication process and the applications of graphene-based electronic devices, including thermal acoustic devices, thermal rectifiers, graphene-based nanogenerators, pressure sensors and graphene-based light-emitting diodes. In summary, although there are still a lot of challenges needing to be solved, graphene-based materials are very promising for various flexible device applications in the future.
Flexible arrays based on the flexible connection of double layers are demonstrated.Flexible sensor arrays are highly desired for many applications.Conventional flexible electronics are implemented by directly fabricating them on organic flexible substrates such as polyimide or polyethylene terephthalate,or forming on rigid substrates and then transferring them onto elastomeric substrates.For the first time,a novel process method based on trench refilling with polydimethylsiloxane to make flexible arrays is proposed.In this method,the sensors are directly fabricated on islands of the final bulk silicon.The performance of the sensor will not to be effected by bending and stretching operations.A one-dimensional flexible array shows good flexibility.Since the flexibility process is the last fabrication step,this method is compatible with many micro-electro-mechanical system fabrication technologies and has good yield.
Surface acoustic wave （SAW） devices have been widely used in different fields and will continue to be of great importance in the foreseeable future. These devices are compact, cost efficient, easy to fabricate, and have a high performance, among other advantages. SAW devices can work as filters, signal processing units, sensors and actuators. They can even work without batteries and operate under harsh environments. In this review, the operating principles of SAW sensors, including temperature sensors, pressure sensors, humidity sensors and biosensors, will be discussed. Several examples and related issues will be presented. Technological trends and future developments will also be discussed.
