Ultra-sensitive, One-time Use Hydrogen Sensors Based on Sub-10 nm Nanogaps on an Elastomeric Substrate

Scanning electrochemical microscopy determination of hydrogen flux at liquid|liquid interface with potentiometric probe

“…Although there are numerous methods of sensitive hydrogen detection [8][9][10], only scanning electrochemical microscopy (SECM) allows determining a flux of this analyte generated at ITIES [11]. SECM amperometric detection of hydrogen produced by proton reduction was earlier reported [12][13][14][15][16].…”

Palladium nanogap-based H2 sensors on a patterned elastomeric substrate using nanoimprint lithography

“…Sub-10 nm wide nanogaps in the Pd/PDMS substrate were obtained by controlling the initial H 2 concentration. 21 In that case, the width of the nanogaps decreased with decreasing concentration of the initial feed of H 2 gas. Liquid nitrogen freezing of the Pd/PDMS elastomer substrate and hybrid thin films have also been M a n u s c r i p t 4 investigated in relation to the control of nanogaps.…”

“…For ON-OFF switching operation of the H 2 sensors, the optimal thickness of Pd film was reported to be 9 ~ 11 nm. 21 If the Pd thickness exceeds 12 nm, then the sensors would always operate in the on-state. Pd films thinner than 8 nm lose functionality and would always be in the off state.…”

Cracked titanium film on an elastomeric substrate for highly flexible, transparent, and low-power strain sensors

“…A mechanism by which nanocracks are generated in the Pd film on PDMS substrate was proposed, and a general process on how the nanocracks thus generated respond to hydrogen molecules was also provided [15,17]. However, systematic studies on the expandability of the proposed mechanism to other metals and the crack generation behaviors dependent on the magnitude of applied strain were missing.…”

“…From previous works on palladium (Pd) film on a PDMS substrate, it was demonstrated that the Pd film was broken into pieces under an external or internal strain and it could be applied for highly sensitive hydrogen gas sensors [ 15 - 18 ]. A mechanism by which nanocracks are generated in the Pd film on PDMS substrate was proposed, and a general process on how the nanocracks thus generated respond to hydrogen molecules was also provided [ 15 , 17 ]. However, systematic studies on the expandability of the proposed mechanism to other metals and the crack generation behaviors dependent on the magnitude of applied strain were missing.…”