performance and relatively low cost have been demonstrated as a leading candidate for numerous applications in energy harvesting and self-powered sensing. [1][2][3][4][5] It plays an increasingly important role with the fast depletion of fossil fuels. As an energy harvester, the output characteristic of the TENGs is the key consideration, which involves two main aspects: the surface charge density [6][7][8] and the output impedance. [9,10] Till now, studies have been conducted on the improvement of the surface charge density, such as surface functionalization techniques including micropatterning surface, [11][12][13][14][15][16][17][18][19][20] plasma treatment, [21] or adding chemical functional groups. [22][23][24][25] Especially substantial researches on the TENGs have concentrated on making triboelectric layers into both micro-and nanoscale to achieve increased surface areas and roughness. [26] However, there is a lack of effective means to reduce the output impedance.Plasmonic energy conversion proposed as a high efficiency scheme to electron-hole separation opens up a wide range of applications in the field of subwavelength optics, [27] data storage, [28] nonlinear optics, [29] solar cells, [30] and Adv. Energy Mater. 2019, 9, 1902725 www.advenergymat.de www.advancedsciencenews.com
A piezoelectric AlN-on-SOI structured MEMS Lamb wave resonator (LWR) is presented for high-temperature strain measurement. The LWR has a composite membrane of a 1 μm thick AlN film and a 30 μm thick device silicon layer. The excited acoustic waves include Rayleigh wave and Lamb waves. A tensile strain sensor has been prepared with one LWR mounted on a uniaxial tensile plate, and its temperature characteristics from 15.4°C to 250°C and tensile strain behaviors from 0 με to 400 με of Rayleigh wave and S4 mode Lamb wave were tested. The temperature test verifies the adaptability of the tensile strain sensor to temperature up to 250°C, and S4 mode Lamb wave and Rayleigh wave represent almost the same temperature characteristics. The strain test demonstrates that S4 mode Lamb wave shows much higher strain sensitivity (-0.48 ppm/με) than Rayleigh wave (0.05 ppm/με) and confirms its advantage of strain sensitivity. Finally, for this one-LWR strain sensor, a method of beat frequency between S4 mode Lamb wave and Rayleigh wave is proposed for temperature compensation and high-sensitivity strain readout.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.