Microhotplates for low power, and ultra dense gaseous sensor arrays using recessed silica aerogel for heat insulation

Abstract

Abstract-In the operation of air pitted gaseous sensor the microhotplate (µHP) consumes almost all the power used by the sensor. The required area to micromachine the air pit for the µHP of a single sensor is several times more than the actual area required by the sensor itself. The feasibility of implementing low power and ultra dense gaseous sensor array is investigated by developing a new µHP structure using recessed silica aerogel. In comparison with the conventional µHP structure, the recessed aerogel not only has decreased the utilized area of the chip almost ten folds (181 × 181 µm 2 vs. 573 × 573 µm 2 ) to maintain a temperature of 360 • C but also has decreased the power consumed by each µHP more than two folds (1 mW vs. 2.1 mW ). As the number of sensors increases in a sensor array, the saved area of the chip increases quadratic by using the new structure. Moreover, the power consumed by the new designed structure reduces drastically.

Ultra‐dense and ultra‐low power microhotplates using silica aerogel

“…We have previously simulated the operation of a μHP built on aerogel coated silicon wafers. The simulation result was found to be highly promising [5]. In this Letter, we experimentally verify the previous simulation results by implementing a single layer thin film silica aerogel as a heat insulator on silicon wafers.…”

An Updated Overview of Silica Aerogel-Based Nanomaterials

“…End uses of silica aerogels that have been reported include adsorbents of harmful compounds [ 18 , 19 ], sensors [ 20 ], conductive and dielectric materials, gas filters and storage materials of gases [ 21 ], Cherenkov detectors [ 22 ], kinetic energy absorbers [ 23 ], catalysts and catalyst support [ 21 , 24 ], extraction agents [ 25 , 26 ], and protective clothing [ 27 ]. However, there is no doubt that the most important uses of silica aerogels are in thermal and acoustic insulation [ 28 , 29 ], with numerous in-depth reports in this field [ 30 , 31 , 32 , 33 ].…”