Hybrid and Passive Tissue-Anchoring Mechanism for Ingestible Resident Devices
Hybrid and Passive Tissue-Anchoring Mechanism for Ingestible Resident Devices
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DOI：
10.1109/jmems.2020.2999448
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发表时间：
2020-10
影响因子：
2.7
通讯作者：
Sanwei Liu;Sangwook Chu;L. Beardslee;R. Ghodssi
中科院分区：
文献类型：
--
作者：
Sanwei Liu;Sangwook Chu;L. Beardslee;R. Ghodssi
这项工作提出了一种混合的组织锚定机制，结合了一个预压缩的微弹簧的自主驱动和倒刺微针（MN）的强大的组织锚定与最小的预加载。弹簧微针单元（SMU）允许与潜在的可摄入驻留系统轻松集成，以实现在胃肠道（GI）中的长时间操作（例如，生物标志物监测和治疗药物递送）。利用高精度直接激光写入（DLW），SMU直接在柔性聚酰亚胺基板上制造，该基板可以方便地附接到可摄取设备的外部封装上，以减小形状因子，从而为多功能系统组件节省空间。3D打印的微弹簧可以被压缩并嵌入一层可溶性聚合物（聚乙二醇）薄层中，并在37°C下聚合物溶解在水介质中时以约140- $\mu \text{m}$的位移自主驱动。SMU的机械校准表明，100- $\mu \text{m}$驱动的平均释放力为8 mN。根据我们之前对倒刺MN的研究，该驱动力为MN提供了足够大的预载荷，以实现稳健的组织锚定。最重要的是，这种新颖而有效的组织锚定机制具有很大的潜力，可以使微型生物传感和药物输送系统长期运行。[2020-0169]
This work presents a hybrid tissue-anchoring mechanism that combines a pre-compressed microspring for autonomous actuation and a barbed microneedle (MN) for robust tissue anchoring with minimized preloading. The spring-microneedle unit (SMU) allows facile integration with potential ingestible resident systems to enable prolonged operation in the gastrointestinal (GI) tract (e.g. biomarker monitoring and therapeutic drug delivery). Utilizing high-precision direct laser writing (DLW), the SMU is directly fabricated on a flexible polyimide substrate, which that can be conveniently attached onto the exterior packages of ingestible devices to reduce the form factor and therefore to save room for multifunctional system components. The 3-D printed microspring can be compressed and embedded within a thin layer of dissolvable polymer (polyethylene glycol) and autonomously actuated with a ~140- $\mu \text{m}$ displacement upon polymer dissolution in aqueous media at 37°C. Mechanical calibration of the SMU demonstrated an average release force of 8 mN for a 100- $\mu \text{m}$ actuation. According to our previous research into barbed MNs, this actuation force provides a large enough preload for a MN to achieve robust tissue-anchoring. Above all, the novel and effective tissue-anchoring mechanism has a great potential for enabling long-term operation of miniature biosensing and drug delivery systems. [2020-0169]