The exploration of multifunctional liquid robotics with ferrofluids: Fabrication, control, operation and sensing

• Published in: Nano energy Vol. 131; p. 110169
• Main Authors: Chen, Jingge, Xia, Liangyu, Wu, Xiaohan, Du, Limeng, Liu, Ruiqi, Liu, Jialuo, Li, Xian, Sun, Yuxuan, Colvin, Vicki L., Cao, Quanliang
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2024
• Subjects: Digital display; Ferrofluids; Label-free manipulation; Liquid robotics; Programming control; Sensing; Label-free manipulation; Digital display; Sensing; Programming control; Ferrofluids; Liquid robotics
• ISSN: 2211-2855
• DOI: 10.1016/j.nanoen.2024.110169

Liquid robotics with arbitrary deformability and rich functionality can adapt to various environmental constraints and perform many significant tasks. To turn this vision into reality, an intelligent liquid system, ferrofluid, which possesses excellent macroscopic and microscopic responsiveness to external magnetic fields, is explored as the rudiment of liquid robotics. Focus is given not only to its improved fabrication and cooperative programming control, but also its underexplored object manipulation and signal transmission. The prepared ferrofluid consists of sterically stabilized ultra-small magnetic nanoparticles suspended in carrier liquids, showing strong stability, flexible mobility, and substantial magnetization. Intelligent locomotion and complex morphology control are successfully achieved by a programmable platform that generates sequential pre-designed magnetic fields through the timing activation of specific electromagnets. Meanwhile, by utilizing the magneto-Archimedes effect, this ferrofluid system can perform multi-dimensional manipulation of objects with densities ranging from 1.1 to 8.9 g/cm3 in cooperation with varying magnetic fields. Furthermore, this system can sense vibrations due to its intrinsic liquid feature and send corresponding signals through detecting the changes in magnetic flux by external coils. Similarly, the flow, concentration, and speed of ferrofluids can also be detected. These advancements in fabrication, control, operation, and sensing are crucial for the development of liquid robotics. [Display omitted] •A facile one-pot method for preparing long-term stable ferrofluids was developed.•The flexible locomotion and complex morphology control of a large volume of ferrofluids was achieved.•Ferrofluids could accomplish multi-dimensional label-free manipulation of nonmagnetic objects with a wide density range.•Ferrofluids could sense vibration and their flow, concentration, and speed could also be detected.