Robust Triboelectric Nanogenerator Achieved by Centrifugal Force Induced Automatic Working Mode Transition

Abstract

Material abrasion in contact‐based freestanding mode‐triboelectric nanogenerators (FS‐TENGs) seriously deteriorates device mechanical durability and electrical stability, which causes TENGs to be only applicable in the harvesting of mechanical energy at low‐frequency. Here, a wide‐frequency and ultra‐robust rotational TENG is reported that is composed of a built‐in traction rope structure and capable of transforming from contact mode to non‐contact mode automatically as driven by the centrifugal force. With optimizing the fixed x and y position on slider and center shaft, respectively, the mode transition threshold speed can be reduced to 225 rpm. Additionally, the automatic working mode transition TENG exhibits excellent electrical stability, which can maintain 90% electric output after over 24 h of continuous operation, while the contact and non‐contact mode TENGs only retain 30% and 2% output, respectively. The high stability and large output density ensure its usage in the fast and effective charging of commercial capacitors or electronics. This work provides a prospective strategy for rotational TENGs to extend the frequency operation region and mechanical durability for practical applications.

Progress inTENGtechnology—A journey from energy harvesting to nanoenergy and nanosystem

“…With the aid of electrostatic induction, electrons relating to the surface of materials would flow from one electrode to the other electrode through the external load to obtain a new balance of the potential. [10][11][12][13][14][15] To better explain the charge generation and the charge transfer in the contact interface of TENG, as shown in Figure 2B, an electron cloud potential well model was reported to describe the TENG theory as a function of temperature ( Figure 2B-II). 87 The triboelectric electrons from the instantaneous contact and separation would have flowed from high potential to low potential as shown in Figure 2B-III.…”

“…4,[73][74][75][76][77][78][79] With the benefit of charge generation and transfer, the various self-powered sensors with their unique functions were well-developed, such as the physical sensors, the chemical/gas sensors, and the fluid sensors. 14,22,23,55,80,81 Beyond its excellent energy harvesting capability and wide collection of selfpowered sensors it enables, TENG can also be easily integrated into NENS to detect or interact with its surrounding environment, such as blue energy sensor nodes, wearable sensors/human-machine interfaces (HMIs), neural interfaces/implanted devices, and optical interfaces/wearable photonics. [66][67][68][69][70][71][72]77 Furthermore, by integrating with other potential technologies for a sustainable system, TENG hence unlocks a vast pool of applications targeting properties like more power output, self-healing, and synergy with IoT in the intelligent world.…”

Simultaneously Enhancing Power Density and Durability of Sliding‐Mode Triboelectric Nanogenerator via Interface Liquid Lubrication

“…However, this strategy is not well applicable for enhancing output performance of sliding-mode DC-TENG, and a violent friction during sliding process always generate abrasion, thus causing poor durability of TENG. In addition, although replacing sliding motion to rolling movement in sliding TENG, [21,22] applying automatic mode transition between contact and noncontact mode in FS-TENG, [23,24] and introducing liquid lubrication in sliding TENG [25] have been reported to reduce wear behavior of sliding-mode TENG, simultaneously achieving high power output have not been involved. Therefore, a universal strategy to simultaneously enhance power output by suppressing air breakdown and improve durability of both sliding-mode AC-TENG and sliding-mode DC-TENG is highly desired.…”

Dynamical charge transfer for high‐performance triboelectric nanogenerators

“…Chen et al tuned the charge decay characteristic time of the triboelectric material by changing the frequency of periodic mechanical motion, giving rise to a higher average surface charge density for materials with larger decay coefficients. [47] Compared to electret materials with months to decades, the charge decay characteristic time of a triboelectric material is only a few minutes to a few days. [48] Despite the large decay coefficient value, some materials are promising as they have higher ε r , higher E breakdown , and/or larger σ i for optimization.…”

“…[39,40,49] Loss of surface charge also originates from other factors, such as light, [50] humidity [2,5] and material abrasion. [47] A better understanding of the decay coefficient and the interaction with other enhancement mechanisms will enable more innovative highperformance triboelectric materials efforts.…”