Zhang Jiachen, Onaizah Onaizah, Sadri Amir, Diller Eric
Department of Mechanical & Industrial Engineering, University of Toronto, Toronto, Ontario, M5S 3G8, Canada.
Bio-Rad Laboratories (Canada) Ltd., 1329 Meyerside Drive, Mississauga, Ontario, L5T 1C9, Canada.
Biomed Microdevices. 2017 Jun;19(2):43. doi: 10.1007/s10544-017-0183-2.
Cell sorters play important roles in biological and medical applications, such as cellular behavior study and disease diagnosis and therapy. This work presents a label-free microfluidic sorter that has a downstream-pointing magnetic elastic diverter. Different with most existing magnetic sorters, the proposed device does not require the target microobjects to be intrinsically magnetic or coated with magnetic particles, giving users more flexibility in sorting criteria. The diverter is wirelessly deformed by an applied magnetic field, and its deformation induces a fluid vortex that sorts incoming microobjects, e.g., cells, to the collection outlet. The diverter does not touch samples in this process, reducing the sample contamination and damage risks. This sorter uses a magnetic field generated by off-chip electromagnetic coils that are centimeters away from the device. With simple structure and no on-chip circuits or coils, this device can be integrated with other lab-on-a-chip instruments in a sealed chip, ameliorating the safety concerns in handling hazardous samples. The parallel and independent control of two such diverters on a single chip were demonstrated, showing the potential of doubling the overall throughput or forming a two-stage cascaded sorter. The sorter was modeled based on the Euler-Bernoulli beam theory and its reliability was demonstrated by achieving a raw success rate of 96.68% in sorting 1506 registered microbeads. With a simple structure, the sorter is easy and cheap to fabricate. The advantages of the proposed sorter make it a promising multi-purpose sorting tool in both academic and industrial applications.
细胞分选仪在生物学和医学应用中发挥着重要作用，如细胞行为研究以及疾病诊断与治疗。这项工作展示了一种无标记微流控分选仪，其具有一个向下游指向的磁性弹性分流器。与大多数现有的磁性分选仪不同，该所提出的装置不要求目标微物体本身具有磁性或包覆磁性颗粒，这在分选标准方面给予了用户更大的灵活性。分流器在施加的磁场作用下无线变形，其变形会诱导流体涡旋，从而将进入的微物体（如细胞）分选到收集出口。在此过程中，分流器不接触样本，降低了样本污染和损坏风险。该分选仪使用由离设备数厘米远的片外电磁线圈产生的磁场。由于结构简单且无片上电路或线圈，该装置可与其他芯片实验室仪器集成在一个密封芯片中，改善了处理危险样本时的安全问题。在单个芯片上展示了对两个这样的分流器的并行和独立控制，显示出使整体通量翻倍或形成两级级联分选仪的潜力。基于欧拉 - 伯努利梁理论对该分选仪进行了建模，并通过在分选1506个已登记微珠时达到96.68%的原始成功率证明了其可靠性。该分选仪结构简单，易于制造且成本低廉。所提出的分选仪的优点使其成为学术和工业应用中一种有前景的多功能分选工具。
