Amid the growing interest in triboelectric nanogenerators(TENGs)as novel energy-harvesting devices,several studies have focused on direct current(DC)TENGs to generate a stable DC output for operating electronic device...Amid the growing interest in triboelectric nanogenerators(TENGs)as novel energy-harvesting devices,several studies have focused on direct current(DC)TENGs to generate a stable DC output for operating electronic devices.However,owing to the working mechanisms of conventional DC TENGs,generating a stable DC output from reciprocating motion remains a challenge.Accordingly,we propose a bidirectional rotating DC TENG(BiR-TENG),which can generate DC outputs,regardless of the direction of rotation,from reciprocating motions.The distinct design of the BiR-TENG enables the mechanical rectification of the alternating current output into a rotational-direction-dependent DC output.Furthermore,it allows the conversion of the rotational-direction-dependent DC output into a unidirectional DC output by adapting the configurations depending on the rotational direction.Owing to these tailored design strategies and subsequent optimizations,the BiR-TENG could generate an effective unidirectional DC output.Applications of the BiR-TENG for the reciprocating motions of swinging doors and waves were demonstrated by harnessing this output.This study demonstrates the potential of the BiR-TENG design strategy as an effective and versatile solution for energy harvesting from reciprocating motions,highlighting the suitability of DC outputs as an energy source for electronic devices.展开更多
The spontaneously generated electrical charge of a droplet dispensed from conventional pipetting is undesirable and unpredictable for most experiments that use pipetting.Hence,a method for controlling and removing the...The spontaneously generated electrical charge of a droplet dispensed from conventional pipetting is undesirable and unpredictable for most experiments that use pipetting.Hence,a method for controlling and removing the electrical charge needs to be developed.In this study,by using the electrode-deposited pipet tip(E-pipet tip),the charge-controlling system is newly developed and the electrical charge of a droplet is precisely controlled.The effect of electrolyte concentration and volume of the transferred solution to the electrical charge of a dispensed droplet is theoretically and experimentally investigated by using the equivalent capacitor model.Furthermore,a proof-of-concept example of the self-alignment and self-assembly of sequentially dispensed multiple droplets is demonstrated as one of the potential applications.Given that the electrical charge of the various aqueous droplets can be precisely and simply controlled,the fabricated E-pipet tip can be broadly utilized not only as a general charge-controlling platform of aqueous droplets but also as a powerful tool to explore fundamental scientific research regarding electrical charge of a droplet,such as the surface oscillation and evaporation of charged droplets.展开更多
As the first invention to efficiently harvest electricity from ambient mechanical energy by using contact electrification, the triboelectric nanogenerator has elicited worldwide attention because of its cost-effective...As the first invention to efficiently harvest electricity from ambient mechanical energy by using contact electrification, the triboelectric nanogenerator has elicited worldwide attention because of its cost-effectiveness and sustainability. This study exploits a superhydrophobic nanostructured aluminum tube to estimate electrical output for solid-water contact electrification inside a tubular system. The linearly proportional relationship of short-circuit current and open-circuit voltage to the detaching speed of water was determined by using a theoretical energy harvesting model and experimentation. A pioneering stick-type solid-water interacting triboelectric nanogenerator, called a SWING stick, was developed to harvest mechanical energy through solid-water contact electrification generated when the device is shaken by hand. The electrical output generated by various kinds of water from the environment was also measured to demonstrate the concept of the SWING stick as a compact triboelectric nanogenerator. Several SWING sticks were connected to show the feasibility of the device as a portable and compact source of direct power. The developed energy harvesting model and the SWING stick can provide a guideline for the design parameters to attain a desired electrical output; therefore, this study can significantly increase the applicability of a water-driven triboelectric nanogenerator.展开更多
Electrical stimulation has recently received attention as noninvasive treatment in skin wound healing with its outstanding biological property for clinical setting.However,the complexity of equipment for applying appr...Electrical stimulation has recently received attention as noninvasive treatment in skin wound healing with its outstanding biological property for clinical setting.However,the complexity of equipment for applying appropriate electrical stimulation remains an ongoing challenge.Here,we proposed a strategy for skin scar inhibition by providing electrical stimulation via a multilayer stacked electret(MS-electret),which can generate direct current(DC)electric field(EF)without any power supply equipment.In addition,the MS-electret can easily control the intensity of EFs by simply stacking electret layers and maintain stable EF with the surface potential of 3400 V over 5 days owing to the injected charges on the electret surface.We confirmed inhibition of type 1 collagen andα-SMA expression of human dermal fibroblasts(hDFs)by 90%and 44%in vitro,indicating that the transition of hDFs to myofibroblasts was restricted by applying stable electrical stimulation.We further revealed a 20%significant decrease in the ratio of myofibroblasts caused by the MS-electret in vivo.These findings present that the MS-electret is an outstanding candidate for effective skin scar inhibition with a battery-free,physiological electrical microenvironment,and noninvasive treatment that allows it to prevent external infection.展开更多
基金This work was supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.2022R1C1C1008831).This work was also supported by the Human Resources Development of the Korea Institute of Energy Technology Evaluation and Planning(KETEP)grant funded by the Ministry of Trade,Industry and Energy of Korea(No.RS-2023-00244330).S J P was supported by Basic Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(No.2018R1A6A1A03025526).
文摘Amid the growing interest in triboelectric nanogenerators(TENGs)as novel energy-harvesting devices,several studies have focused on direct current(DC)TENGs to generate a stable DC output for operating electronic devices.However,owing to the working mechanisms of conventional DC TENGs,generating a stable DC output from reciprocating motion remains a challenge.Accordingly,we propose a bidirectional rotating DC TENG(BiR-TENG),which can generate DC outputs,regardless of the direction of rotation,from reciprocating motions.The distinct design of the BiR-TENG enables the mechanical rectification of the alternating current output into a rotational-direction-dependent DC output.Furthermore,it allows the conversion of the rotational-direction-dependent DC output into a unidirectional DC output by adapting the configurations depending on the rotational direction.Owing to these tailored design strategies and subsequent optimizations,the BiR-TENG could generate an effective unidirectional DC output.Applications of the BiR-TENG for the reciprocating motions of swinging doors and waves were demonstrated by harnessing this output.This study demonstrates the potential of the BiR-TENG design strategy as an effective and versatile solution for energy harvesting from reciprocating motions,highlighting the suitability of DC outputs as an energy source for electronic devices.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIP).(No.2014R1A2A1A010065272011-0030075+1 种基金2012R1A2A2A06047424)supported by the convergence technology development program for bionic arm through the National Research Foundation of Korea(NRF)funded by the Ministry of Science,ICT&Future Planning(No.2014M3C1B2048632)
文摘The spontaneously generated electrical charge of a droplet dispensed from conventional pipetting is undesirable and unpredictable for most experiments that use pipetting.Hence,a method for controlling and removing the electrical charge needs to be developed.In this study,by using the electrode-deposited pipet tip(E-pipet tip),the charge-controlling system is newly developed and the electrical charge of a droplet is precisely controlled.The effect of electrolyte concentration and volume of the transferred solution to the electrical charge of a dispensed droplet is theoretically and experimentally investigated by using the equivalent capacitor model.Furthermore,a proof-of-concept example of the self-alignment and self-assembly of sequentially dispensed multiple droplets is demonstrated as one of the potential applications.Given that the electrical charge of the various aqueous droplets can be precisely and simply controlled,the fabricated E-pipet tip can be broadly utilized not only as a general charge-controlling platform of aqueous droplets but also as a powerful tool to explore fundamental scientific research regarding electrical charge of a droplet,such as the surface oscillation and evaporation of charged droplets.
文摘As the first invention to efficiently harvest electricity from ambient mechanical energy by using contact electrification, the triboelectric nanogenerator has elicited worldwide attention because of its cost-effectiveness and sustainability. This study exploits a superhydrophobic nanostructured aluminum tube to estimate electrical output for solid-water contact electrification inside a tubular system. The linearly proportional relationship of short-circuit current and open-circuit voltage to the detaching speed of water was determined by using a theoretical energy harvesting model and experimentation. A pioneering stick-type solid-water interacting triboelectric nanogenerator, called a SWING stick, was developed to harvest mechanical energy through solid-water contact electrification generated when the device is shaken by hand. The electrical output generated by various kinds of water from the environment was also measured to demonstrate the concept of the SWING stick as a compact triboelectric nanogenerator. Several SWING sticks were connected to show the feasibility of the device as a portable and compact source of direct power. The developed energy harvesting model and the SWING stick can provide a guideline for the design parameters to attain a desired electrical output; therefore, this study can significantly increase the applicability of a water-driven triboelectric nanogenerator.
基金National Research Foundation of Korea(NRF),Grant/Award Numbers:2021R1A4A1032782,2022R1C1C1008831Korean Fund for Regenerative Medicine(KFRM),Grant/Award Number:21A0102L1-12Postdoctoral Research Program of Sungkyunkwan University。
文摘Electrical stimulation has recently received attention as noninvasive treatment in skin wound healing with its outstanding biological property for clinical setting.However,the complexity of equipment for applying appropriate electrical stimulation remains an ongoing challenge.Here,we proposed a strategy for skin scar inhibition by providing electrical stimulation via a multilayer stacked electret(MS-electret),which can generate direct current(DC)electric field(EF)without any power supply equipment.In addition,the MS-electret can easily control the intensity of EFs by simply stacking electret layers and maintain stable EF with the surface potential of 3400 V over 5 days owing to the injected charges on the electret surface.We confirmed inhibition of type 1 collagen andα-SMA expression of human dermal fibroblasts(hDFs)by 90%and 44%in vitro,indicating that the transition of hDFs to myofibroblasts was restricted by applying stable electrical stimulation.We further revealed a 20%significant decrease in the ratio of myofibroblasts caused by the MS-electret in vivo.These findings present that the MS-electret is an outstanding candidate for effective skin scar inhibition with a battery-free,physiological electrical microenvironment,and noninvasive treatment that allows it to prevent external infection.
