Hourglass Triboelectric Nanogenerator as a "Direct Current" Power Source

Chuan He, Chang Bao Han, Guang Qin Gu, Tao Jiang, Bao Dong Chen, Zhen Liang Gao, Zhong Lin Wang
2017 Advanced Energy Materials  
energies of various forms, such as wind, [9, 10] human motion, [11, 12] and water waves, [13, 14] into electricity. Generally, TENGs have a periodic mechanical motion and hence deliver an alternating current (AC) output in the external circuit. So, it needs to be used in combination with a rectifier bridge to get a direct current (DC) output. In this regard, efforts have been made to fabricate TENGs with DC output characteristics. Previously, a DC TENG has been presented to capture energy from
more » ... he rotation motion of two wheels, however, it needed a Corona discharge to pass the electrons through an external load. [15] Another DC TENG has also been introduced to acquire rotational mechanical energy based on a rotating disk design. [16] In this paper, we demonstrate an hourglass triboelectric nanogenerator (HG-TENG) that extracts the kinetic energy of the falling particles. The particles used are a mixture of polytetrafluoroethylene (PTFE) pellets and aluminum (Al) balls. Through a unique design of the electrode, the HG-TENG directly converts kinetic energy of the falling particles into a train of electrical pulses of the same sign without a rectifier bridge. The electrical pulses produced can light up 160 serially connected commercial light emitting diodes (LEDs) intermittently for 18 s. Furthermore, the HG-TENG also demonstrates its capability as a self-powered UV counterfeit detector. Figure 1a illustrates the structural design of the HG-TENG. The HG-TENG contains two identical funnels that are vertically connected by a tube and the conical mouth of each funnel is covered by a pillar electrode. The pictures of the bottom funnel and the pillar electrode are shown in Figure 1a -i,ii, respectively. The bottom funnel is filled with a mixture of PTFE pellets and Al balls. An enlarged view of the mixed particles is displayed in Figure 1a -iii. The diameters of the particles used are both around 2 mm. As illustrated in Figure 1a -ii, the pillar electrode consists of two parts: the vertically aligned Al pillars, which are tailored to the geometry of the funnel, and the Al plate at the bottom. The detailed description of the HG-TENG is presented in the Experimental Section. The operating process Hourglass, or sandglass, is known for centuries to record the passage of time. Here, an hourglass triboelectric nanogenerator (HG-TENG) is reported as a power source by harnessing the kinetic energy of falling particles. By employing the geometry of an hourglass and replacing the sand with a mixture of polytetrafluoroethylene (PTFE) pellets and Al balls, the HG-TENG delivers a train of electrical pulses of the same sign without a rectifier bridge. When the volume ratio of the PTFE pellets to the Al balls is 1:1, the HG-TENG is able to light up 160 commercial light emitting diodes intermittently for 18 s. Furthermore, it is demonstrated that the HG-TENG can also serve as a self-powered UV counterfeit detector. Results and Discussion
doi:10.1002/aenm.201700644 fatcat:mdojishmlzbgvhdrsvo2ote674