Flexible surface acoustic wave strain sensor based on single crystalline LiNbO3 thin film

Abstract

Flexible surface acoustic wave (SAW) sensors in the frequency range of 162~325 MHz were developed based on single crystalline LiNbO 3 thin film with dual resonance modes, namely the Rayleigh mode and thickness shear mode (TSM). This SAW sensor could handle a wide strain range up to ±3500 µε owing to its excellent flexibility, which is nearly six times the detecting range of bulk piezoelectric substrate based SAW strain sensors. The sensor exhibited a high sensitivity of 193 Hz/µε with a maximum hysteresis less than 1.5%, much better than those commercially available metallic strai gauges. The temperature coefficients of frequency, for Rayleigh and TSM modes, were-85 and-59 ppm/℃, respectively. No visible deterioration was observed after cyclic bending for hundreds of times, showing its desirable stability and reliability. By utilizing the dual modes, the strain sensor with a self-temperature calibrated capability can be achieved. The results demonstrate that the sensor is an excellent candidate for strain sensing.

Progress in the Triboelectric Human–Machine Interfaces (HMIs)-Moving from Smart Gloves to AI/Haptic Enabled HMI in the 5G/IoT Era

“…Another strategy to realize battery-free sensor nodes with continuous sensing capability under the IoT framework is to use passive wireless technologies, including near-field communication (NFC) [329,330], radio frequency identification (RFID) [331,332], and surface acoustic wave (SAW) sensors [333,334]. Compared with the abovementioned wireless transmission methods based on the TENG output enabled electric/magnetic coupling, these passive wireless approaches commonly show better stability in varying environmental circumstances, as well as smaller wireless sensing and receiving units.…”

Mode Analysis of Pt/LGS Surface Acoustic Wave Devices

“…In hostile environments such as gas turbines [ 15 ], high temperature, high pressure and large strain often coexist, and monitoring these parameters is very crucial for machine state monitoring and structure health maintenance. Based on the application scenarios, Pt LGS SAW device(s) with more than one acoustic wave mode would be very attractive as multi-mode sensing can be utilized for single chip multi-parameter monitoring or temperature compensation by a differential method [ 16 , 17 , 18 ]. It was reported that the large mass loading of Pt, nearly eight times heavier than aluminum (Al), could affect the reflection coefficient of LGS SAW devices, and induce multiple modes excitation and interactions between them [ 19 ].…”

The Photorefractive Response of Zn and Mo Codoped LiNbO3 in the Visible Region

“…Volume holographic storage is a technology that can store information at high density inside a crystal, which exploits the "inside" of the storage material, rather than only using its surface, resulting in a massive increase in the capacity of the data storage. Lithium niobate (LN) crystal is an essential material in many applications [1][2][3][4][5], such as surface acoustic wave, waveguides, volume holographic storage, piezoelectric, pyroelectric, and integrated optics [6][7][8][9]. The performance of volume holographic storage is particularly prominent [10][11][12][13][14][15][16][17][18].…”