Key Laboratory of Bionic Engineering, Ministry of Education, Jilin University, Changchun 130022, China.
School of Mechanical and Aerospace Engineering, Jilin University, Changchun 130022, China.
ACS Nano. 2021 Dec 28;15(12):19629-19639. doi: 10.1021/acsnano.1c06843. Epub 2021 Dec 2.
Flexible strain sensors have an irreplaceable role in critical and emerging fields, such as electronic skins, flexible robots, and prosthetics. Although numerous efforts have been made to improve sensor sensitivity to meet specific application scenarios, the signal-to-noise ratio (SNR) is an extremely critical and non-negligible indicator, which takes into account higher sensitivity, meaning that they can also detect the noise signals with high sensitivity. Coincidentally, scorpions with ultrasensitive vibration sensilla also face such a dilemma. Here, it is found that the scorpion ingeniously uses the viscoelastic material in front of its slit sensilla to realize efficient preprocessing of the signal. Its mechanism is that the loss factor of materials changes with frequency, affecting energy storage and transmission. Inspired by this ingenious strategy, a bioinspired strain sensor insensitive to a low strain rate was designed using a two-step template transfer method. As a result, its relative change in resistance reached 110% under the same strain (0.3197%) but with different strain rates (0.1 Hz and ∼20 Hz). The noncontact vibration experiments also show different responses to low-frequency vibration and high-frequency impact. Moreover, it can also be used as a typical flexible strain sensor. Under the tensile state, it has a gauge factor (GF) as high as 4596 upon 0.6% strain, and the response time is 140 ms. Therefore, it is expected that this strain sensor will be used in many important ultraprecision measurement fields, especially when the measured signal is small.
柔性应变传感器在电子皮肤、柔性机器人和假肢等关键和新兴领域具有不可替代的作用。尽管已经做出了许多努力来提高传感器的灵敏度以满足特定的应用场景，但信噪比（SNR）是一个极其关键且不可忽视的指标，它考虑到了更高的灵敏度，这意味着它们也可以高灵敏度地检测噪声信号。巧合的是，具有超灵敏振动感受器的蝎子也面临着这样的困境。在这里，人们发现蝎子巧妙地利用其狭缝感受器前面的粘弹性材料来实现对信号的有效预处理。其机制是材料的损耗因子随频率变化，影响能量的存储和传递。受此巧妙策略的启发，使用两步模板转移方法设计了一种对低应变速率不敏感的仿生应变传感器。结果，在相同应变（0.3197%）但不同应变速率（0.1 Hz 和 ∼20 Hz）下，其电阻的相对变化达到 110%。非接触式振动实验还表明，它对低频振动和高频冲击有不同的响应。此外，它还可以用作典型的柔性应变传感器。在拉伸状态下，应变达到 0.6%时，其应变系数（GF）高达 4596，响应时间为 140ms。因此，预计这种应变传感器将在许多重要的超精密测量领域得到应用，特别是在测量信号较小时。
