- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Morphologically modulated laser-patterned reduced graphene oxide strain sensors for human fatigue recognition
摘要： Laser heating provides an effective method to produce thermally reduced graphene oxide (rGO), it can also pattern the designed layout on the surface of graphene oxide (GO) during the reduction process. In this work, we demonstrated a flexible strain sensor based on the morphologically modulated laser-patterned reduced graphene oxide (LPG) film with a one-step process. Compared with the strain sensor using flat patterned rGO (0-1.2%) and curved-grid patterned rGO (CGPG) (0-4.1%), the strain sensor based on rectangular-grid patterned rGO (RGPG) have highest gauge factor (GF), up to 133 under 2.7% of physical deformation. Meanwhile, the RGPG strain sensors exhibit extraordinary linearity in a relatively large range of deformation (0-2.7%) and excellent endurance for over 1000 stretching-releasing circles. The RGPG strain sensor was used to monitor human fatigue. By analyzing eye blinking frequency and duration, it is possible to evaluate the fatigue level. We anticipate that the RGPG based strain sensor, prepared via a relatively simple and cost-effective process, may open up a broad spectrum of practical applications, such as driver fatigue evaluation and smart monitoring of human body movements.
关键词： wearable electronics,laser patterning,fatigue evaluation,flexible strain sensor,reduced graphene oxide
更新于2025-09-12 10:27:22
-
Flexible dual-mode SAW strain sensor based on crystalline LiNbO3 thin film
摘要： This work presents the development of flexible dual-mode surface acoustic wave (SAW) sensor based on single crystalline thin film lithium niobate (TF-LN). Numerical modeling is conducted to investigate the SAW propagation and the effects on strain sensitivity. The dependence of strain sensitivity on angles between the applied strain and SAW propagation direction is analyzed numerically and experimentally, showing that the maximum strain sensitivity is at 45° rather than longitudinal direction. 128° Y-cut TF-LN (~50 μm), obtained by micromachining technique, is utilized as the piezoelectric substrate to fabricate the SAW strain sensors with dual mode, namely Rayleigh mode and thickness shear mode (TSM). The sensor has excellent flexibility and demonstrates remarkable capability for an ultra-wide range strain measurement up to ±3000 με. Temperature effects on resonant frequency and strain sensitivity are investigated in the range of 25 ~ 100 ℃, and similar temperature characteristics are observed for the dual modes. A method of beat frequency between the dual modes is introduced which is able to eliminate the temperature effect on strain sensing, an on-chip temperature influence removing capability. All the results clearly show that this sensor exhibits great potential for applications in flexible electronics and microsystems.
关键词： dual-mode,temperature cancellation,flexible strain sensor,LiNbO3 thin film,surface acoustic wave
更新于2025-09-09 09:28:46