Recent technological advances have led to the development of novel 3D printed micromachines that have been found useful in various applications, including micromixers, micro-swimmers, micropumps and micro-transporters.
University of Illinois at Chicago (UIC) scientists: Yang Lin (PhD candidate) and Dr. Jie Xu from the Department of Mechanical and Industrial Engineering conducted an in-depth review on the possibilities of combining the two-photon polymerization (TPP) method with various manipulating techniques such as magnetic, optic, and acoustic approaches with intentions of further developing micromachines. They anticipated that the combination of two-photon polymerization associated with remotely driven techniques would have many industrial applications. Their expert opinion is currently published in the research journal, Advanced Optical Materials.
In brief, the authors introduced the essential mechanism behind TPP and relevant photosensitive materials. Next, they assessed and discussed the common treatments that were responsible for the realization of remote manipulations. They then proceeded to effect and elucidate on applications with respect to various types of remotely driven techniques. Lastly, they provided a detailed overview with regard to the observations from their procedure.
The authors discussed that both magnetic and optical techniques were applicable for remotely driving micromachines, however, the latter was more preferable as it did not necessitate extra treatments since the optical tweezer itself had the ability to trap and move micro-objects. Furthermore, the two scholars also noted that other manipulations techniques were also feasible but most were in their early stages of development; in particular, the acoustic manipulation technique.
In summary, the Yang Lin et al study presented a detailed expert review regarding two-photon polymerization as a state-of-the-art 3D fabrication technique for controllable micromachines. In their review, they revisited the essential principles behind the TPP technique and immediate treatments. In addition, they highlighted the critical aspects of the various types of remote manipulation for micromachines giving detailed explanations on their technical aspects. Altogether, this overview of the present developments and has pin-pointed the weaknesses being encountered in this specific area, as well as highlights potential prospective routes that could be followed in the future for further advances.
Indeed, the researchers published several follow-up studies recently, showcasing these advances outlined in their review. In their article published in Advanced Material Interfaces, Yang and co-workers reported the novel usage of TPP for modifying 3D microstructures of surfaces in order to turn them into superhydrophobic surfaces, mimicking lotus leaves with the ability to repel water and keep the surface clean.
In another study published in Microfluidics and Nanofluidics, the authors reported a novel method of utilizing TPP for soft lithography, a method widely used for fabricating microfluidic chips and lab on a chip devices. Very recently, Yang and Dr. Xu have successfully created microfluidic pumps using TPP that is driven by acoustic waves. All these studies suggest that a new wave of technological breakthroughs is ongoing in the field of micromachines, and Yang Lin and Dr. Jie Xu are clearly leading this wave. As young scientists, their potentials are yet to be fully unleashed and they are expected to lead greater advances in the years to come. In fact, most of these studies are supported by Dr. Jie Xu’s NASA Early Career Faculty Award, and Dr. Jie Xu is named the 2018 UIC Rising Star Researcher of the Year in the Natural Sciences and Engineering category. Dr. Xu was previously also a DARPA Young Faculty Awardee and he is an elected member of the Global Young Academy.
Lin, Y., & Xu, J. (2018). Microstructures Fabricated by Two‐Photon Polymerization and Their Remote Manipulation Techniques: Toward 3D Printing of Micromachines. Advanced Optical Materials 2018, volume 6, 1701359Go To Advanced Optical Materials
Lin, Y., Zhou, R., & Xu, J. (2018). Superhydrophobic Surfaces Based on Fractal and Hierarchical Microstructures Using Two‐Photon Polymerization: Toward Flexible Superhydrophobic Films. Advanced Material Interfaces, Volume 5, Issue21, 2018, 1801126Go To Advanced Material Interfaces
Lin, Y., Gao, C., Gritsenko, D., Zhou, R., & Xu, J. (2018). Soft lithography based on photolithography and two-photon polymerization. Microfluid Nanofluid (2018) 22: 97.Go To Microfluid Nanofluid