Single-Walled Carbon Nanotube Pirani Gauges Prepared by DEP Assembly

Abstract

This paper reports the design, fabrication, and characteristics of the single-walled carbon nanotubes (SWNTs) Pirani gauge fabricated by dielectrophoretic assembly first which requires simple equipments and process, costs little, and operates at room temperature without limitation on the materials of electrode and substrate. Its theory and design were described in detail. The characteristics were measured and analyzed systematically such as current-voltage, resistance-temperature, thermal response, resistance-pressure, and power consumption properties. The results show that this SWNTs Pirani gauge has rapid thermal response of milliseconds and can operate at very low power consumption down to 15 nW. It reveals a wide linear dynamic range from 0.8 to 80 000 Pa and high sensitivity about 8 kΩ/Pa on average.

A Miniaturized Low Power Pirani Pressure Sensor Based on Suspended Graphene

“…A nano Pirani pressure sensor based on a CNT implemention exists [1], but it does not have a selective fabrication process. In this research, world's first graphene-based Pirani pressure sensors with a selective fabrication process [6] are presented that are significantly smaller then current implementations and therefore consume less power.…”

Large scale and high yield assembly of SWNTs by sacrificial electrode method

“…And the margin of the electrodes fabricated by sacrificial electrode method was cleaner than the floating type, as we found some SWNT bundles were suspended on the margin of the bias electrode in devices fabricated by floating potential process. In our previous work [9], 500 m long Au lines were designed in order to realize SWNTs assembly in all of the devices on chip. Then we cut off them absolutely by dicing process for electrical separation of all devices.…”

“…The screening length should be larger than the width of electrode in order to get one pair of electrode assembled by single-bundle of SWNTs. The size of our devices fabricated by floating potential method or sacrificial electrode method had already been optimized to avoid the screen effect [9]. The typical size of electrodes were width of 1 m or 3 m and the microgap between opposed electrodes were 3 m. The process of sacrificial electrode method were showed in fig.…”

Optimized MEMS Pirani sensor with increased pressure measurement sensitivity in the fine and rough vacuum regimes

“…By miniaturizing the sensor element, new application fields are gathered. The new sensor elements are much smaller in size and are competitive 2,4,5, [11][12][13]21,[28][29][30][31][32][33][36][37][38]42,45 with or even improved 1,3, 15,17,[23][24][25]43 in sensitivity compared to conventional Pirani gauges. Many designs [6][7][8][9][10][14][15][16][17][18][19][20]22,26,34 have been developed for specific pressure ranges.…”

“…For the rough vacuum regime, there are mainly two different approaches for improving the sensitivity. First, nanowire, 36 nanotube, 37 and nanogap 18 sensors reduce the characteristic length in the system as much as possible. The second promising approach employed to improve the performance in the rough vacuum range is to use the transient response 39,40 of a Pirani sensor that is associated with the changing heat capacity of the gas 41 in this specific range.…”