Enhanced energy harvester performance by a tension annealed carbon nanotube yarn at extreme temperatures

Abstract

Carbon nanotube (CNT) yarn generates electrical energy when it was stretched in an electrolyte, and it has been exploited for diverse applications such as self-powered sensors and human health monitoring...

Fast and Strong Carbon Nanotube Yarn Artificial Muscles by Electro-osmotic Pump

“…The sizes of void space decreased to be comparable with the solvated ion size by squeezing the void space as a result of stretching the yarn. Thus, the solvated ion injection will make muscle expansion more effective when the muscle is prestretched, which even compensates for the decreased number of injected ions due to the decreased capacitance (Figure h) . For PSS@CNT yarn muscle, the increased capacitance with prestrain (Figure h, Figure S5a) additively contributes to stress generation.…”

“…Carbon multiwalled nanotube (MWNT) forests, which were drawable to produce MWNT sheets, were synthesized on silicon wafers by chemical vapor deposition (CVD), using acetylene gas as the carbon source. 30 The resulting forests typically exhibit a height of approximately 300 μm and contain 6 individual walls, as observed by a transmission electron microscope (TEM). The average diameter of the MWNT is ∼9 nm.…”

“…For instance, the addition of graphene to CNT yarns has been shown to increase their electrochemical capacitance by 2.4 times, resulting in a substantial stroke of 8% when driven by a −2 V potential in a 0.5 M sodium sulfate (Na 2 SO 4 ) aqueous electrolyte. 30 Lee et al demonstrated an even larger stroke of 16.5% using a neat, coiled CNT yarn in a 0.2 M triethylammonium tetrafluoroborate (TEA•BF 4 ) in polycarbonate (PC), since this electrolyte allows for a broader electrochemical potential window. 20 However, these electrochemically powered CNT yarn muscles are not effectively utilized across the entire potential range, as the total stroke is canceled a great deal when the potential is scanned between extreme values, thus reducing the muscle's stroke.…”

Recent Advances in Carbon Nanotube‐Based Energy Harvesting Technologies

“…[ 2 ] Moreover, due to their electrochemical charge‐acceptance ability, CNTs can absorb solvated ions and thereby charge electrochemical double‐layer capacitance (EDLC) when they are immersed in a suitable electrolyte, without the need for an externally applied bias potential. These unique properties of CNTs make them attractive for various practical applications such as artificial muscles, [ 3–7 ] supercapacitors, [ 8–10 ] batteries, [ 11,12 ] sensors, [ 13–17 ] wearable devices, [ 18–20 ] and harvesters of mechanical energy [ 1,21–24 ] and thermal energy. [ 25–28 ]…”

“…[2] Moreover, due to their electrochemical charge-acceptance ability, CNTs can absorb solvated ions and thereby charge electrochemical double-layer capacitance (EDLC) when they are immersed in a suitable electrolyte, without the need for an externally applied bias potential. These unique properties of CNTs make them attractive for various practical applications such as artificial muscles, [3][4][5][6][7] supercapacitors, [8][9][10] batteries, [11,12] sensors, [13][14][15][16][17] wearable devices, [18][19][20] and harvesters of mechanical energy [1,[21][22][23][24] and thermal energy. [25][26][27][28] Based on the above advantages, various CNT-based devices have been developed for harvesting ambient energies (such as mechanical energy, hydro energy, solar energy, and thermal energy) with encouraging results.…”