High Efficiency Crumpled Carbon Nanotube Heaters for Low Drift Hydrogen Sensing

Abstract

This work presents the fabrication of crumpled carbon nanotubes (C-CNTs) thin film heaters and their application towards high sensitivity and low drift hydrogen gas sensing. Utilizing a spray coating of pristine multi-walled carbon nanotubes (MWCNTs) and thermal shrinkage of polystyrene (PS) substrate, we have fabricated C-CNTs with closely packed junctions. Joule heating of C-CNTs gives higher temperature at a given input voltage compared to as-deposited CNTs. In addition, temperature coefficient of resistance (TCR) is analyzed for accurate temperature control and measurement of the heater. The C-CNT heaters are capable of hydrogen gas sensing while demonstrating higher measurement sensitivities along with lower drift compared to as-deposited CNT devices. In addition, the self-heating of C-CNT heaters help rapid desorption of hydrogen, and thus allowing repetitive and stable sensor operation. Our findings reveal that both CNT morphologies and heating temperatures affect the hydrogen sensing performances.

Recent trends in gas sensingviacarbon nanomaterials: outlook and challenges

“…175 In the same year, Park et al sensed H 2 on MWCNTs and crumpled MWCNTs on a PET and polystyrene (PS) substrate, respectively, and observed that the crumpled CNTs showed 3.25 times higher sensitivity than MWCNTs. 176 Moreover, it has also been reported that for the enhancement of the sensing response towards H 2 gas, the presence of functionalized groups on the surface of CNTs such as COOH and OH plays a crucial role. 177 Furthermore, together with CNTs, Pd is generally used due to its high catalytic activity towards H 2 gas.…”

“… 175 In the same year, Park et al sensed H 2 on MWCNTs and crumpled MWCNTs on a PET and polystyrene (PS) substrate, respectively, and observed that the crumpled CNTs showed 3.25 times higher sensitivity than MWCNTs. 176 …”

Fabrication of High-Performance CNT Reinforced Polymer Composite for Additive Manufacturing by Phase Inversion Technique

“…The MWCNT has a negative temperature coefficient of resistance (TCR), representing the semiconductor essence of MWCNTs [41]. In the filament, increasing temperature up to 75 • C decreased the resistance, and the resistance increase after 75 • C was due to thermal expansion of the polymer matrix (Figure 8c).…”

Facile electro-thermal igniters based on freestanding CNTs films for the ignition of energetic materials

“…To exert the electro-thermal function, CNTs can be used in the form of self-assembled films/papers or fillers in multi-component composite materials [4][5][6][7][8]. Among them, CNTs-based film heaters have attracted great attention in anti-/de-icing systems [9][10][11], self-healing materials [12], smart actuators [13], sensors [14] and so on because of their good flexibility, fast thermal response, light weight, low cost and facile preparation. Recently, CNTs-based film heaters have found new applications in the ignition of energetic materials.…”