Highly aligned suspended nanowire array for self-heating type gas sensors

Cho

et al. 2022

Small

The demand for power‐efficient micro‐and nanodevices is increasing rapidly. In this regard, electrothermal nanowire‐based heaters are promising solutions for the ultralow‐power devices required in IoT applications. Herein, a method is demonstrated for producing a 1D nanoheater by selectively coating a suspended pyrolyzed carbon nanowire backbone with a thin Au resistive heater layer and utilizing it in a portable gas sensor system. This sophisticated nanostructure is developed without complex nanofabrication and nanoscale alignment processes, owing to the suspended architecture and built‐in shadow mask. The suspended carbon nanowires, which are batch‐fabricated using carbon‐microelectromechanical systems technology, maintain their structural and functional integrity in subsequent nanopatterning processes because of their excellent mechanical robustness. The developed nanoheater is used in gas sensors via user‐designable localization of the metal oxide semiconductor nanomaterials onto the central region of the nanoheater at the desired temperature. This allows the sensing site to be uniformly heated, enabling reliable and sensitive gas detection. The 1D nanoheater embedded gas sensor can be heated immediately to 250 °C at a remarkably low power of 1.6 mW, surpassing the performance of state‐of‐the‐art microheater‐based gas sensors. The presented technology offers facile 1D nanoheater production and promising pathways for applications in various electrothermal devices.

Section: Introductionmentioning

confidence: 99%

“…Therefore, the entire gas‐sensing site must be uniformly heated for gas detection with high reliability and sensitivity. [ 23–25 ]…”

Section: Introductionmentioning

confidence: 99%

Batch Nanofabrication of Suspended Single 1D Nanoheaters for Ultralow‐Power Metal Oxide Semiconductor‐Based Gas Sensors

Cho

et al. 2022

Small

“…A number of hydrogen sensors have therefore been proposed that use the hydrogen absorption characteristic of Pd. These include resistive type sensors, 3,4 work functionbased sensors, [5][6][7] and capacitive MEMS sensors. 8 Resistive sensors utilize the fact that the electrical resistance of Pd changes with hydrogen absorption.…”

Section: Introductionmentioning

confidence: 99%

A review of capacitive MEMS hydrogen sensor using Pd‐based metallic glass with fast response and low power consumption

Yamazaki

Hayashi

Masunishi

et al. 2019

Elect Comm in Japan

This paper reports on a capacitive MEMS hydrogen sensor using Pd‐based metallic glass (MG) for future hydrogen society. First, we investigate PdCuSi as a Pd‐based MG and show that this material is promising for capacitive MEMS hydrogen sensor. Second, we employ the Pd‐based MG in a hydrogen sensor that has an inverted T‐shaped electrode. The sensor is fabricated by a surface micromachining process. We show that the fabricated hydrogen sensor exhibits hysteresis‐free and fast response properties at room temperature.

“…1 However, hydrogen is a flammable gas, and hydrogen leaks need to be detected promptly. These include resistive type sensors, 3,4 work functionbased sensors, [5][6][7] and capacitive MEMS sensors. In addition, low power consumption is important for continuous monitoring in battery driven devices.…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A Review of Capacitive MEMS Hydrogen Sensor using Pd based Metallic Glass with Fast Response and Low Power Consumption

et al. 2018

This paper reports on a capacitive MEMS hydrogen sensor using Pd-based metallic glass (MG) for future hydrogen society. First, we investigate PdCuSi as a Pd-based MG and show that this material is promising for capacitive MEMS hydrogen sensor. Second, we employ the Pd-based MG in a hydrogen sensor that has an inverted Tshaped electrode. The sensor is fabricated by a surface micromachining process. We show that the fabricated hydrogen sensor exhibits hysteresis-free and fast response properties at room temperature. K E Y W O R D Scapacitive, hydrogen sensor, hydrogen society, MEMS, Pd-based metallic glass 2 SENSING FILMS Pd-based metallic glassPd has excellent hydrogen absorption characteristics but hydrogen is absorbed as a metal hydride, and as a result, the response to hydrogen is slow, and heat is required to release 70