Hao Ren
Junrui Liang
Jicheng Feng
Xiaosheng Zhang- 1School of Information Science and Technology, ShanghaiTech University, Shanghai, China
- 2School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
- 3School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, China
Editorial on the Research Topic
Miniaturized Bioenergy and Energy Harvesting Systems
Miniaturized energy harvesting systems, such as miniaturized microbial fuel cells, biological fuel cells, triboelectric energy harvesters, piezoelectric energy harvesters, represent an emerging area of research and have found a great potential for developing self-powered wireless sensor networks (WSN), Internet of Things (IoT), and portable electronics applications. Nowadays, power supply remains one of the major critical issues for the development of WSN and IoT. Semiconductor chips in the systems enjoy the scaling effect from miniaturization. The scaling effect means that when the size of devices is small, they have a higher surface area to volume ratio, smaller size, less expense, and faster frequency response. As a result, a variety of miniaturized sensors, actuators, and microsystems have taken advantage of the scaling effect, such as microprocessors, accelerometers, gyroscopes, micromirrors, actuators, biosensors, and resonators, etc. (Yazdi et al., 1998; Chae et al., 2005; Hu et al., 2010; Ren et al., 2011; Ren et al., 2013; Wang et al., 2014; Yeap et al., 2019; Fei and Ren, 2021). However, traditional power supplies, such as lithium-ion batteries, suffer from lower capacity due to miniaturization and often require frequent replacement after deployment. As a result, it is critical to develop miniaturized energy harvesting systems, which are self-sustainable, for these emerging applications.
Microbial fuel cells are bionic-based electrochemical fuel cells that directly convert the chemical energy stored in organic compounds from biomass into electrical energy (Logan and Rabaey, 2012; Ren et al., 2015; Ren et al., 2016a; Ren et al., 2016b). This is accomplished through the catalytic reaction of specific microorganisms called exoelectrogens or Anode-Respiring Bacteria (ARB) (Torres et al., 2008). Microbial fuel cell represents a carbon-neutral and renewable energy converter. Miniaturized MFCs have smaller chamber volumes compared with macro or mesoscale MFCs, and they are generally fabricated by microfabrication techniques. The surface area to volume ratio of miniaturized MFCs is high, resulting in a higher current and power density (Ren et al., 2012). Although the current and power densities significantly boosted in the past 2 decades, however, the current and power densities of miniaturized microbial fuel cells are still lower than conventional energy conversion and storage devices, such as lithium-ion batteries. The approaches which have the potential to further improve the current and power density of miniaturized microbial fuel cells are discussed in this topic by (Ren).
Biological fuel cells are fuel cells that convert chemical energy stored in organic compounds into electricity with the catalytic activity of biological enzymes or living entities. Compared with conventional energy conversion and storage devices, such as the lithium-ion battery, biological fuel cells can utilize the organic compounds in the environment and living entities, and it also represents a carbon-neutral and renewable energy converter (Li et al., 2020a). Miniaturized biological fuel cells utilize microfabrication and microfluidics techniques to reduce their size and they have the potential to be implemented into power sources for implantable medical devices. In this research topic, Maza et al. present a low-cost glucose/O2 Y-shaped microfluidic biofuel cell that was developed using a printed circuit board (Mashayekhi Mazar et al., 2021). They implemented a double-side tape based on the pressure-sensitive adhesive to fabricate the microfluidic channel for the microfluidic biofuel cell. The electrode was coated with a nanocomposite that consisted of reduced graphene oxide gold nanoparticles (AuNPs). Aspergillus niger glucose oxidase enzyme and Mytheliophthora thermophile laccase were used to modify the anodic and cathodic electrodes. A maximum power density of 36 μW/cm2 and an open-circuit voltage of 0.5 V are reported at a flow rate of 50 μL/min.
Triboelectric energy harvesters, also named triboelectric nanogenerator (TENG), implement triboelectricity, which is static-electricity charges generated by contact and motion between surfaces. When two materials are brought into contact and separated, the electric charge separation and induction process occur, and electricity is generated. Since its invention in 2012 (Fan et al., 2012), triboelectric energy harvesters have found many applications in self-powered systems, such as wearable sensors (Wen et al., 2019), trajectory-tracking microsystems (Ba et al., 2021), magnetic sensors (Yang et al., 2012), chemical sensors (Huang et al., 2021), etc. In this research topic, Zhao and Zhu discuss the application of triboelectric nanogenerator in smart home and clothing applications (Zhao and Zhu). For smart home applications, triboelectric energy harvesters can be implemented for switch sensors for smart home lighting fixtures, pressure sensors for home floors, power supply for home security systems, etc. For clothing applications, triboelectric energy harvesters can be implemented for sensing the frequency and acceleration when integrated into shoe sole, absorbing static electricity on clothes and reducing the static electricity on clothes, and sensing gestures when integrated into smart gloves, etc.
Piezoelectric energy harvesters utilize the piezoelectric effect to convert mechanical energy into electrical energy. The piezoelectric effect arises when a strain is produced on piezoelectric materials. Positive and negative charges accumulate on the two opposite surfaces of the piezoelectric materials, respectively. If we connect a load between the two surfaces with opposite charges, current flows. Thus mechanical strain energy is converted into electrical energy. Nowadays, piezoelectric energy harvesters have been widely implemented for self-powered systems and IoT applications, such as vibration- or motion-powered sensing and transmitting systems (Li et al., 2020b), self-powered motion detection systems (Li et al., 2021), and self-powered wearable upper limb (Liu et al., 2021). In this research topic, Guo et al. presented a theoretical and experimental study of the vibration dynamics of a 3D-printed sandwich beam with an hourglass lattice truss core. It has a provided potential solution to explore the advantages of using sandwich beams for piezoelectric energy harvesting (Guo et al.).
In addition to the miniaturized energy harvesters, power management systems are also critical as the output power from the energy harvesters cannot be directly used to drive the loads. Power management electronics are necessary for energy harvesting systems. The power management circuits aim to convert the output of the energy harvesters to voltage levels which can be directly fed to load, such as wireless sensors or IoT devices. A variety of power management systems for microbial fuel cells, biological fuel cells, triboelectric energy harvesters, and piezoelectric energy harvesters have been reported (Liang and Liao, 2011; Zhang et al., 2014; Xu et al., 2017; Liang et al., 2018; Liang et al., 2019). Due to the advantage of self-powering, carbon-neutral, and renewable characteristics, the miniaturized bioenergy and energy harvesting systems integrated with power management circuits may provide solutions to powering billions of WSN or IoT systems in the future.
Author Contributions
HR wrote the original editorial, JL, JF, and XZ revised the editorial.
Conflict of Interest
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Publisher’s Note
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References
Ba, Y.-Y., Bao, J.-F., Wang, Z.-Y., Deng, H.-T., Wen, D.-L., Zhang, X.-R., et al. (2021). Self-powered Trajectory-Tracking Microsystem Based on Electrode-Miniaturized Triboelectric Nanogenerator. Nano Energy 82, 105730. doi:10.1016/j.nanoen.2020.105730
Fan, F.-R., Tian, Z.-Q., and Lin Wang, Z. (2012). Flexible Triboelectric Generator. Nano Energy 1, 328–334. doi:10.1016/j.nanoen.2012.01.004
Fei, S., and Ren, H. (2021). Temperature Characteristics of a Contour Mode MEMS AlN Piezoelectric Ring Resonator on SOI Substrate. Micromachines 12, 143. doi:10.3390/mi12020143
Hu, F., Yao, J., Qiu, C., and Ren, H. (2010). A MEMS Micromirror Driven by Electrostatic Force. J. Electrostatics 68, 237–242. doi:10.1016/j.elstat.2010.01.005
Huang, C., Chen, G., Nashalian, A., and Chen, J. (2021). Advances in Self-Powered Chemical Sensing via a Triboelectric Nanogenerator. Nanoscale 13, 2065–2081. doi:10.1039/d0nr07770d
Chae, J., Kulah, H., and Najafi, K. (2005). A Monolithic Three-axis Micro-g Micromachined Silicon Capacitive Accelerometer. J. Microelectromech. Syst. 14, 235–242. doi:10.1109/jmems.2004.839347
Li, X., Lv, P., Yao, Y., Feng, Q., Mensah, A., Li, D., et al. (2020). A Novel Single-Enzymatic Biofuel Cell Based on Highly Flexible Conductive Bacterial Cellulose Electrode Utilizing Pollutants as Fuel. Chem. Eng. J. 379, 122316. doi:10.1016/j.cej.2019.122316
Li, X., Tang, H., Hu, G., Zhao, B., and Liang, J. (2021). ViPSN-pluck: A Transient-Motion-Powered Motion Detector. IEEE Internet Things J., 1. doi:10.1109/jiot.2021.3098238
Li, X., Teng, L., Tang, H., Chen, J., Wang, H., Liu, Y., et al. (2020). ViPSN: A Vibration-Powered IoT Platform. IEEE Internet of Things Journal.
Liang, J., and Liao, W.-H. (2011). Improved Design and Analysis of Self-Powered Synchronized Switch Interface Circuit for Piezoelectric Energy Harvesting Systems. IEEE Trans. Ind. Electronics 59, 1950–1960.
Liang, J., Zhao, Y., and Zhao, K. (2018). Synchronized Triple Bias-Flip Interface Circuit for Piezoelectric Energy Harvesting Enhancement. IEEE Trans. Power Electronics 34, 275–286.
Liang, X., Jiang, T., Liu, G., Xiao, T., Xu, L., Li, W., et al. (2019). Triboelectric Nanogenerator Networks Integrated with Power Management Module for Water Wave Energy Harvesting. Adv. Funct. Mater. 29, 1807241. doi:10.1002/adfm.201807241
Liu, Y., Khanbareh, H., Halim, M. A., Feeney, A., Zhang, X., Heidari, H., et al. (2021). Piezoelectric Energy Harvesting for Self‐powered Wearable Upper Limb Applications. Nano Select.
Logan, B. E., and Rabaey, K. (2012). Conversion of Wastes into Bioelectricity and Chemicals by Using Microbial Electrochemical Technologies. Science 337, 686–690. doi:10.1126/science.1217412
Ren, H., Lee, H.-S., and Chae, J. (2012). Miniaturizing Microbial Fuel Cells for Potential Portable Power Sources: Promises and Challenges. Microfluid Nanofluid 13, 353–381. doi:10.1007/s10404-012-0986-7
Ren, H., Pyo, S., Lee, J.-I., Park, T.-J., Gittleson, F. S., Leung, F. C. C., et al. (2015). A High Power Density Miniaturized Microbial Fuel Cell Having Carbon Nanotube Anodes. J. Power Sourc. 273, 823–830. doi:10.1016/j.jpowsour.2014.09.165
Ren, H., Rangaswami, S., Lee, H.-S., and Chae, J. (2016). Enhanced Current and Power Density of Micro-scale Microbial Fuel Cells with Ultramicroelectrode Anodes. J. Micromech. Microeng. 26, 095016. doi:10.1088/0960-1317/26/9/095016
Ren, H., Tao, F., Wang, W., and Yao, J. (2011). An Out-Of-Plane Electrostatic Actuator Based on the Lever Principle. J. Micromech. Microeng. 21, 045019. doi:10.1088/0960-1317/21/4/045019
Ren, H., Tian, H., Gardner, C. L., Ren, T.-L., and Chae, J. (2016). A Miniaturized Microbial Fuel Cell with Three-Dimensional Graphene Macroporous Scaffold Anode Demonstrating a Record Power Density of over 10 000 W M−3. Nanoscale 8, 3539–3547. doi:10.1039/c5nr07267k
Ren, H., Wang, W., Tao, F., and Yao, J. (2013). A Bi-directional Out-Of-Plane Actuator by Electrostatic Force. Micromachines 4, 431–443. doi:10.3390/mi4040431
Torres, C. I., Kato Marcus, A., and Rittmann, B. E. (2008). Proton Transport inside the Biofilm Limits Electrical Current Generation by Anode-Respiring Bacteria. Biotechnol. Bioeng. 100, 872–881. doi:10.1002/bit.21821
Wang, R., Wang, W., Ren, H., and Chae, J. (2014). Detection of Copper Ions in Drinking Water Using the Competitive Adsorption of Proteins. Biosens. Bioelectron. 57, 179–185. doi:10.1016/j.bios.2014.01.056
Wen, D.-L., Liu, X., Deng, H.-T., Sun, D.-H., Qian, H.-Y., Brugger, J., et al. (2019). Printed Silk-Fibroin-Based Triboelectric Nanogenerators for Multi-Functional Wearable Sensing. Nano Energy 66, 104123. doi:10.1016/j.nanoen.2019.104123
Xu, Z., Liu, Y., Williams, I., Li, Y., Qian, F., Wang, L., et al. (2017). Flat Enzyme-Based Lactate Biofuel Cell Integrated with Power Management System: Towards Long Term In Situ Power Supply for Wearable Sensors. Appl. Energ. 194, 71–80. doi:10.1016/j.apenergy.2017.01.104
Yang, Y., Lin, L., Zhang, Y., Jing, Q., Hou, T.-C., and Wang, Z. L. (2012). Self-powered Magnetic Sensor Based on a Triboelectric Nanogenerator. ACS Nano 6, 10378–10383. doi:10.1021/nn304374m
Yazdi, N., Ayazi, F., and Najafi, K. (1998). Micromachined Inertial Sensors. Proc. IEEE 86, 1640–1659. doi:10.1109/5.704269
Yeap, G., Lin, S., Chen, Y., Shang, H., Wang, P., Lin, H., et al. (2019). IEEE, 36.7. 1–36.7. 4.5nm CMOS Production Technology Platform Featuring Full-Fledged EUV, and High Mobility Channel FinFETs with Densest 0.021 Μm 2 SRAM Cells for Mobile SoC and High Performance Computing Applications2019 IEEE International Electron Devices Meeting (IEDM).
Keywords: microsystems, energy harvesting, piezoelectric energy harvester, self-powered system, ambient energy, bioenergy
Citation: Ren H, Liang J, Feng J and Zhang X (2021) Editorial: Miniaturized Bioenergy and Energy Harvesting Systems. Front. Mech. Eng 7:741190. doi: 10.3389/fmech.2021.741190
Received: 14 July 2021; Accepted: 28 September 2021;
Published: 22 October 2021.
Edited and reviewed by:
Ajay Giri Prakash Kottapalli, University of Groningen, NetherlandsCopyright © 2021 Ren, Liang, Feng and Zhang. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
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