Seedless Hydrothermal Growth of ZnO Nanorods as a Promising Route for Flexible Tactile Sensors

Nanomaterials

Alessandro Fraleoni Morgera¹  Pramod Kumar²  Magdalena Kowalczyk³  Pasqualantonio Pingue⁴  Calogero Maria Oddo⁵  Giacomo D’Alesio⁵  Domenico Camboni⁵  Alessandro Lucantonio⁵  Luca Massari⁵  Ilaria Cesini⁵  Antonio DeSimone⁵ 

[1] Department of Engineering and Architecture, University of Trieste, 34127 Trieste, Italy;Department of Physics, Indian Institute of Technology Bombay, Mumbai 400076, India;Institute of Automation and Robotics, Poznan University of Technology, 60-965 Poznan, Poland;NEST Laboratory, Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa, Italy;The BioRobotics Institute, Scuola Superiore Sant’Anna, Viale Rinaldo Piaggio 34, 56025 Pontedera, Italy;

关键词: ZnO nanorods;    Seedless hydrothermal growth;    Finite-Element Analysis;    PDMS-embedded devices;    Tactile sensors;    Flexible substrates;   

DOI  :  10.3390/nano10050977

来源: DOAJ

【 摘 要 】

Hydrothermal growth of ZnO nanorods has been widely used for the development of tactile sensors, with the aid of ZnO seed layers, favoring the growth of dense and vertically aligned nanorods. However, seed layers represent an additional fabrication step in the sensor design. In this study, a seedless hydrothermal growth of ZnO nanorods was carried out on Au-coated Si and polyimide substrates. The effects of both the Au morphology and the growth temperature on the characteristics of the nanorods were investigated, finding that smaller Au grains produced tilted rods, while larger grains provided vertical rods. Highly dense and high-aspect-ratio nanorods with hexagonal prismatic shape were obtained at 75 °C and 85 °C, while pyramid-like rods were grown when the temperature was set to 95 °C. Finite-element simulations demonstrated that prismatic rods produce higher voltage responses than the pyramid-shaped ones. A tactile sensor, with an active area of 1 cm², was fabricated on flexible polyimide substrate and embedding the nanorods forest in a polydimethylsiloxane matrix as a separation layer between the bottom and the top Au electrodes. The prototype showed clear responses upon applied loads of 2–4 N and vibrations over frequencies in the range of 20–800 Hz.

【 授权许可】

Unknown