Zhou Aiwu, Xu Changyu, Kanitthamniyom Pojchanun, Ng Chelsea Shan Xian, Lim Gerard Joseph, Lew Wen Siang, Vasoo Shawn, Zhang Xiaosheng, Lum Guo Zhan, Zhang Yi
Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore.
School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore.
Adv Mater. 2022 Apr;34(15):e2200061. doi: 10.1002/adma.202200061. Epub 2022 Mar 7.
3D printing via vat photopolymerization (VP) is a highly promising approach for fabricating magnetic soft millirobots (MSMRs) with accurate miniature 3D structures; however, magnetic filler materials added to resin either strongly interfere with the photon energy source or sediment too fast, resulting in the nonuniformity of the filler distribution or failed prints, which limits the application of VP. To this end, a circulating vat photopolymerization (CVP) platform that can print MSMRs with high uniformity, high particle loading, and strong magnetic response is presented. After extensive characterization of materials and 3D printed parts, it is found that SrFe O is an ideal magnetic filler for CVP and can be printed with 30% particle loading and high uniformity. By using CVP, various tethered and untethered MSMRs are 3D printed monolithically and demonstrate the capability of reversible 3D-to-3D transformation and liquid droplet manipulation in 3D, an important task for in vitro diagnostics that are not shown with conventional MSMRs. A fully automated liquid droplet handling platform that manipulates droplets with MSMR is presented for detecting carbapenem antibiotic resistance in hazardous biosamples as a proof of concept, and the results agree with the benchmark.
通过光固化3D打印是制造具有精确微型3D结构的磁性软微型机器人（MSMR）的一种非常有前景的方法；然而，添加到树脂中的磁性填充材料要么会强烈干扰光子能量源，要么沉降太快，导致填充剂分布不均匀或打印失败，这限制了光固化的应用。为此，提出了一种循环光固化（CVP）平台，该平台可以以高均匀性、高颗粒负载和强磁响应打印MSMR。在对材料和3D打印部件进行广泛表征后，发现SrFeO是CVP的理想磁性填充剂，可以以30%的颗粒负载和高均匀性进行打印。通过使用CVP，各种系留和非系留MSMR被整体3D打印，并展示了可逆的3D到3D转换和3D中的液滴操纵能力，这是传统MSMR无法完成的体外诊断的一项重要任务。作为概念验证，提出了一个使用MSMR操纵液滴的全自动液滴处理平台，用于检测危险生物样本中的碳青霉烯抗生素耐药性，结果与基准相符。
