Flexible Film‐Discharge‐Switch Assisted Universal Power Management System for the Four Operation Modes of Triboelectric Nanogenerators

Abstract

energy from nature and the human body, and to power billions of distributed electronics and sensor networks. [1,2] Compared with traditional energy generators, TENG has demonstrated great advantages in efficiency, flexibility, lightweight, environmentally friendly, and environmental adaptability. [3][4][5] As a brand-new invention by Z. L. Wang in 2012, [6] TENG takes a tremendous advancement in various aspects, such as triboelectric mechanism, [7][8][9] structure optimization, [10,11] material research, [12][13][14] application extension, [15][16][17][18] output power, [19,20] direct current (DC) TENG, [21][22][23] and power management system (PMS). [24] However, TENG still has some problems to be addressed. For example, the energy-transfer efficiency from TENG to loads in real applications is not optimal. The reason is that TENG always mismatches with the impedance of load when directly powering electronics or storing electricity generated by the triboelectrification effect. Fortunately, as a bridge between TENG and electronics to reduce the mismatch and improve the energy-transfer efficiency, [24] PMS is invented. Consisting of a temporary storage capacitor (C t ), a switch, and a buck circuit, [25][26][27][28][29] PMS converts random energy from TENG into a steady DC power supply for driving electronics in high efficiency. For example, with and without a high-performance PMS in practical applications, the speed of energy storage in a capacitor can differ by two orders of magnitude. [30] Furthermore, the improvement is reported many times, such as quickly starting up and simultaneously driving multiple devices. [25,28,30,31] The remarkable value of PMS has attracted a lot of attention and leads to various designs, following the same principle and similar topological structures but with different switch designs. [24,25,28] The study of switches, as the key component of PMS, becomes the main effort. In the early stage of switch development (from 2013), reported switches start the PMS field but are bounded together with and followed the movement of TENG, indicating the lowest adaptability in applications. [27,30,[32][33][34][35][36] In the next development stage (from 2015), to investigate the principle of PMS, many active electronic switches are proposed and studied. [25,28,29] Using metal-oxide Triboelectric nanogenerators (TENGs) are used to harvest high entropy energy. To optimize the energy harvesting, storage and effective utilization, a critical part is the power management system (PMS), which requires an ideal electrical switch as the key component. However, the current switch technologies cannot adapt and enhance the charging for the four operation modes of TENG simultaneously. Herein, a flexible film-discharge-switch (FDS), delivering an averaged charge-enhance factor over 100 under four operation modes of TENG, compared to directly charging a capacitor with conventional rectifier is reported. More specifically, the charge-enhancement factors of the FDS are 134.3, 64.7, 97.0, and 136.5 for the modes of ...

Asymmetric-Internal-Capacitance-Induced Charge Aggregation for the Hot-Surface Triboelectric Nanogenerator

“…52−57 A film-discharge switch (FDS) developed in our previous work is applied in this PMS to perform automatic instant discharge. 58 More details are shown in the Experimental 4.3.…”

“…The energy stored in the capacitor, whose power supply voltage is recorded by Keithley 6514, is used for driving several electron devices. Figure S11 shows the detail of PMS, fabricated on a 2 × 4 cm 2 PCB board. − A film-discharge switch (FDS) developed in our previous work is applied in this PMS to perform automatic instant discharge . More details are shown in the Experimental .…”

Achieving high-efficiency triboelectric nanogenerators by suppressing the electrostatic breakdown effect

“…Therefore, the power management circuit (PMC), including an AC-DC converter and a DC-DC step-down voltage regulator, is indispensable to bridge the gap between the TENG and electronic devices. 19 Recently, much progress has been made with the PMC to realize a high energy conversion efficiency, [20][21][22][23] but the PMC enabling high output energy density from TENGs is still lacking (Table S1, ESI †), which greatly restricts the output capability and widespread applications of TENGs. This is mainly due to the variable capacitance of the TENG during working.…”

“…Recently, much progress has been made with the PMC to realize a high energy conversion efficiency, 20–23 but the PMC enabling high output energy density from TENGs is still lacking (Table S1, ESI†), which greatly restricts the output capability and widespread applications of TENGs. This is mainly due to the variable capacitance of the TENG during working.…”

Contact-sliding-separation mode triboelectric nanogenerator

“…Since TENGs were invented in 2012 by Zhong Lin Wang's group, 6 they have become a research hotspot due to their high output performance, 7,8 extensive materials choice, 9,10 low cost, 11,12 and flexible design. 13,14 Previous studies have demonstrated that TENGs can capture energy from the environment and provide power to various electronic sensors. 15,16 However, surface wear and heat generation in the triboelectrification process severely affect the stability of the output performance and limit the lifetime of TENGs.…”