A film bulk acoustic wave resonator (FBAR)-based sensor for the simultaneous measurement of temperature and pressure with high sensitivity is fabricated and characterized. Temperature or pressure sensing is determined by the change in the series resonant frequency of the FBAR device when exposed to a measurement environment. For temperature sensing, measurement results show a sensitivity of 25.02 ppm/ C, a nonlinearity less than AE0:005% over the measurement range of 10 to 80 C, and a hysteresis within AE0:005% in one temperature cycle. In pressure sensing, measured results show a sensitivity of 336.2 ppm/ bar, a nonlinearity less than AE0:004% over the measurement pressure range of 0 to 2.07 bar, and a hysteresis within AE0:007% in one pressure cycle.

This paper presents the fabrication and characterization of a three-dimensional (3D) thermopile; consists of 71 Cu-Ni seriesconnected thermocouples on polyimide (PI) flexible substrate. Using wet etching to etch through 25 mm PI, the cold and hot junctions of thermocouples are formed on the top and bottom surfaces of PI substrate. This 3D layout design differentiates its innovative uniqueness from the traditional 2D planar thermopiles that have both hot and cold junctions on the same plane. The experimental studies on the PI etching with respect to the concentrations of KOH and C 2 H 7 NO in the etching solution conclude that the optimal composition of the etchant is 7 -9 M KOH with 2 -4 M C 2 H 7 NO and etched at 80 C. A measured sensitivity of 0.44 mV/K is realized in the fabricated device. The temperatures measured by the 3D thermopile are very close to those obtained with a digital thermometer, demonstrating that 3D flexible thermopiles has great potential to provide low cost thermal sensor.

No abstract

Two-dimensional staggered silver nanosheets (NSs) immobilized on a flat aluminium foil have been synthesized by keeping the underside surface of the foil in contact with the solution of normal silver mirror reaction. The NSs are hundreds of nanometres to several micrometres in dimensions and tens of nanometres in thickness. The effects of the aluminium foil, a chemically active substrate, on the orientation growth of silver nanosheets has been revealed. The results demonstrated that the growth and the morphology control of the silver nanostructure were simply realized in one process by the introduction of a chemically active substrate.

A novel and simple kind of dual-band monopole MEMS membrane antenna fabricated on silicon suspended parylene membrane is presented. This parylene membrane is a flexible polymer film and it can be coated on various shapes and surfaces of materials or even peeled off from materials as thin flexible substrate. Because of its low deposition processing temperature, it is possible to be fabricated on CMOS circuits post process with MEMS technology. This folded monopole parylene membrane antenna provides two resonant paths of different lengths to achieve the desired dual-band (2.4/5.2GHz) operation for Bluetooth and WLAN application. The low cost, easy fabrication, easily stickable and peel-off flexible properties of this parylene membrane makes it very attractive and convenient in any wireless portable devices such as mobile phone, RFID tag, Bluetooth and WLAN devices, even any wearable clothes...etc.