On July 19, 2021, the research team led by Professor Guo Hengyu of the School of Physics, Chongqing University, published a research paper titled A Mobile and Self-Powered Micro-Flow Pump d on Triboelectricity Driven Electroosmosis in Advanced Materials of Wiley (influence factor: 30.8), in collaboration with the team led by Academician Wang Zhonglin of the Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences. Chongqing University is the first signatory organization. Sun Jianfeng and Zhang Lingjun are first co-authors. Guo Hengyu, Peng Yan and Wang Zhonglin are corresponding co-authors.
Micro-flow system is an experimental platform that integrates biological/chemical/medical/environmental reaction, separation, detection and other processes into a small chip with designed micro-channels, and is called "chip laboratory". It has been widely used in the research and development of various research fields. In micro-flow system, micro-flow pump is its core component, which is used to drive and control micro-flow liquid to work in the chip. As such, it has great significance. Compared with mechanical pressure pump and thermal gradient driven pump, electroosmotic pump (EOP) is widely used in micro-flow system because of its advantages such as easy manufacture, constant fluid velocity and high integration. The electroosmotic pump is usually controlled by changing the size and direction of the electric field in the electric double layer region causing electroosmotic flow (EOF). Therefore, in this case, an external high voltage (HV) DC power supply must be used to manipulate electroosmosis. In addition, the high-voltage power supply has the advantages such as large volume, high cost and insecurity. Furthermore, it is able to form bubbles near the electrode and generate Joule heat, which will affect the micro-flow efficiency. This limits the miniaturization and portability of the micro-flow system based on electroosmosis to a great extent. Therefore, at this stage, there is a great need for an economical, portable, safe, efficient and controllable electroosmotic pump to produce high pressure.
In this paper, an ultra-portable and motion-controlled triboelectric osmotic pump (TEOP) driven by a friction nano-generator is reported for the first time. In the experiment, the sliding mode friction nano-generator produces an open circuit voltage of about 35 kV and short-circuit charge of about 1 μC. It is used as a high-voltage power supply to drive the electroosmotic pump. The production performance of electroosmosis and the operation mechanism of friction electroosmosis pump are systematically characterized and analyzed. The results show that the sliding distance and speed of the friction nano-generator can accurately control the electroosmotic flow (accuracy: 0.4nl). The micro flow and pump pressure of the friction electroosmotic pump of a single micro-channel (depth: 60μm; width: 100 μm; length: 20 mm) can reach ≈ 600 NL · min-1 and ≈ 300 Pa respectively, and have Joule heat as low as 1.76 J cm-3 · nL-1. However, the flow rate of the electroosmotic pump driven by the traditional high-voltage source at the same voltage is only 50 nL · min-1, and Joule heat generated is up to 8.12 J cm-3 · nL-1. Finally, constant and continuous electroosmotic flow is realized by using rotating friction nano-generator, and its application in micro-cooling system and drug delivery and mixing is successfully demonstrated. Based on the above advantages, triboelectric osmotic pump has great potential in economic, portable, safe and motion-controlled micro-flow generation, and can contribute to the diversity of micro-flow systems.
This Project has been supported by the National Natural Science Foundation of China, the operating expense for basic scientific researches in colleges and universities allocated by the central government, Scientific Research Foundation for Doctors of Chongqing Normal University and Qidong Research Foundation of Chongqing University.
Link of the paper: https://doi.org/10.1002/adma.202102765
