Development of a Multiwalled Carbon Nanotube Voltage Sensor Using Copper Oxide Nanofluids

Abstract

Carbon Nanotubes (CNT) are allotropes of carbon having superior mechanical, electronic, physical, and optical properties. When a fluid is passed through the nanotubes, the fluid exerts a mechanical force on the walls of the CNT due to which a strain is induced on the surface of the carbon nanotubes creating a net charge at the center of the strained hexagon. This induced polarity produces a voltage across the nanotubes. In this project, nanofluids (cuprous oxide in ethylene glycol) in addition to conventional fluids were passed through multi-walled carbon nanotubes, and a voltage was observed (upto 4.1 mV in the case of nanofluids) after the capillary rise of the flowing fluid in the nanotube sensor. This was in agreement with previously conducted studies on the piezoelectric effect due to the flow of conventional fluids on single-walled carbon nanotubes. The voltage generated across the multi-walled carbon nanotubes (MWCNTs) for the different fluid systems was compared and characterization was done with respect to the fluid system. An attempt was made to present voltage generated as a function of the fluid and flow properties. The paper aims to highlight the possible use of MWCNTs in sensor-based technology and energy conversion devices.