Dramatically Enhanced Mechanosensitivity and Signal‐to‐Noise Ratio of Nanoscale Crack‐Based Sensors: Effect of Crack Depth

Abstract

The sensitivity of a nanoscale crack-based sensor is enhanced markedly by modulating the crack depth. The crack-depth-propagated sensor exhibits ≈16 000 gauge factor at 2% strain and a superior signal-to-noise ratio of ≈35, which facilitates detection of target signals for voice-pattern recognition.

Fabrication of a Highly Sensitive Stretchable Strain Sensor Utilizing a Microfibrous Membrane and a Cracking Structure on Conducting Polymer

“…As shown in Figure 8, the gauge factor increased more than 40-fold (≈0. [3][4][5][6][7][8][9][10][11][12][13][14]. The resistance change exhibited an unstable profile during strain unloading for both sensors.…”

“…A number of studies have explored the development of wearable strain sensors to detect human motion in medical, sports, and entertainment applications. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] In general, typical human joint movements generate strains of 50%, [14] so a highly stretchable strain sensor capable of measuring strains larger than 50% is necessary for wearable motion-detection applications. Although conventional strain sensors have a well-established technology www.advancedsciencenews.com www.mme-journal.de sensor is very simple compared with traditional strain sensors, which require complex nanomaterial formations or complicated lithography processes.…”

Polyimide Encapsulation of Spider-Inspired Crack-Based Sensors for Durability Improvement

“…The reason why the sensitivity increased first and then decreased was that deepening of crack depth by penetration and incomplete recovery of crack gap by residual stress occurred simultaneously. When a crack penetrates into the substrate, sensitivity increases by deepening the crack depth [16]. However, repetitive straining accumulates residual stress on the crack vertex, disturbing closing of the crack gap, causing the gauge factor to decrease [37].…”

“…Interestingly, it shows that by only changing substrates from PET to PI, sensitivity increased up to 10 times. We assume that this phenomenon was caused by crack penetration into the PI substrate because the sensitivity of the sensor increases as the depth of crack increases [16]. Figure S6 † shows the change in resistance of three samples when applied strain from zero to two percent.…”

“…Where ∆R is the resistance change with deformation, R 0 is the resistance before deformation, and ε is the applied deformation. Moreover, it has diverse advantages including flexibility, wearability, and multifunctional sensing abilities [13][14][15][16][17]. However, the durability of the sensor in harsh environments of liquids and/or high temperature is still a challenging issue.…”