Saturday, November 04, 2023

Einstein Made It Famous; Tech Makes It Current. Generating electricity through Brownian Motion

Amazing stuff! Huge potential or more of a curiosity?

"There are many ways to convert the movement of liquids into electricity, such as, in the form of hydropower or tidal power. But there’s another kind of movement available in liquids that has rarely been considered for this purpose—molecular thermal motion or Brownian motion. ...
Molecular motion has traditionally been an impediment in engineering on a nanoscale, but recent developments in nanotechnology have also allowed scientists to use this phenomenon to their advantage. In a recent study from China, scientists posit that the internal, molecular motion of liquids could be a source of energy if only there was a way to harvest it. To demonstrate, they built a prototype of a molecular thermal motion harvester (MTMH). ...
To use Brownian movement as a source of energy, the researchers had to design a device that could capture and convert the motion into electricity. To make their harvester, they used nanowire arrays made of zinc oxide (ZnO) and gold-coated ZnO as electrodes. ZnO is a piezoelectric material, which means it produces an electric charge in response to mechanical stress, such as bending or flexing, from the Brownian movement of the liquid medium, which in this case was n-octane, with a purity of greater than 99.99 percent. The gold-coated ZnO nanoarray was used as a negative electrode, the plain ZnO one as positive, and the entire device—2 by 2 centimeters in size—was sealed with epoxy. ...
The prototype yielded a stable output voltage of 2.28 millivolts and current of 2.47 nanoamperes at room temperature, though the latter number goes up as temperature rises. ..."

"Abstract
Molecular thermal motion has been studied but yet never been utilized as an energy source. In this work, we demonstrate that the energy of liquid molecular thermal motion can be converted into electrical energy by a novel harvesting device, the molecular thermal motion harvester (MTMH). The MTMH was made by using two ZnO-based nano-arrays and one of which was gold coated to form a Schottky junction. The assembled electrodes were immersed in different liquid phase environments. The device was demonstrated to convert the molecule thermal energy of the liquid into a continuous and stable electric current. The output voltage and current can achieve 2.28 mV and 2.47 nA, respectively, and increase with the liquid temperatures. This strategy opens new insights into the development of mini- and micro-scale energy sources, and it can be expected the MTMH will have broad applications in the future."

Einstein Made It Famous; Tech Makes It Current - IEEE Spectrum Brownian motion is age-old, but its potential for nanoscale electricity is new


Fig. 1 The structure of ZnO nanoarrays and the fabrication process of MTMH. (a) The surface micrograph of ZnO nanoarrays. (b) A detailed surface micrograph of ZnO nanoarrays. (c) The cross-section micrograph of the ZnO nanoarray. (d) The fabrication process of MTMH.


No comments: