A zinc oxide nanowire pressure sensor

[摘要] ENGLISH ABSTRACT: Measurement of pressure with zinc oxide (ZnO) nanowires was investigated.ZnO exhibits the piezoelectric effect, generating a voltage when pressure isapplied to the material. This relationship between pressure and output voltagewas used to make a pressure sensor. A study of the physical and mathematicalworking of the piezoelectric effect in ZnO nanowires was done. Simulationswere conducted by means of specialised software to test the theory.The simulations gave results as the theory had predicted. ZnO nanowireswere grown using various methods. Vapour liquid solid (VLS) was foundto be the best method to grow uniform and dense arrays of ZnO nanowires.Statistical methods were employed to obtain the optimal parameters for thegrowth of ZnO nanowires through the VLS method. After the growth ofthe ZnO nanowires a pressure sensor was built. The manufacturing of thepressure sensor consisted of different steps. The sensors were tested to verifythat they worked as described in theory and as shown in the simulations. Theoutput voltage was lower than the simulated value due to imperfections andlosses throughout the system. The output voltage versus applied pressuregraphs did coincide with the bulk ZnO materials as well as related products,such as force sensing resistors. The output voltage is too low, but there arevarious methods by which the output voltage can be increased. These methodsare discussed. The finished sensor can be used to continuously monitorpressure on a plane.

[发布机构] Stellenbosch University