Embedding microfluidic architectures with microneedles enables fluid management capabilities that present new degrees of freedom for transdermal drug delivery. To this end, fabrication schemes that can simultaneously create and integrate complex millimeter/centimeter-long microfluidic structures and micrometer-scale microneedle features are necessary. Accordingly, three-dimensional (3D) printing techniques are suitable candidates because they allow the rapid realization of customizable yet intricate microfluidic and microneedle features. However, previously reported 3D-printing approaches utilized costly instrumentation that lacked the desired versatility to print both features in a single step and the throughput to render components within distinct length-scales. Here, for the first time in literature, we devise a fabrication scheme to create hollow microneedles interfaced with microfluidic structures in a single step. Our method utilizes stereolithography 3D-printing and pushes its boundaries (achieving print resolutions below the full width half maximum laser spot size resolution) to create complex architectures with lower cost and higher print speed and throughput than previously reported methods. To demonstrate a potential application, a microfluidic-enabled microneedle architecture was printed to render hydrodynamic mixing and transdermal drug delivery within a single device. The presented architectures can be adopted in future biomedical devices to facilitate new modes of operations for transdermal drug delivery applications such as combinational therapy for preclinical testing of biologic treatments.

中文翻译：

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3D打印的微流体功能空心微针架构，用于透皮给药。

将微流体体系结构与微针嵌入在一起可以实现流体管理功能，从而为透皮药物输送提供了新的自由度。为此，需要能够同时创建和集成复杂的毫米/厘米长的微流体结构和微米级微针特征的制造方案。因此，三维（3D）打印技术是合适的选择，因为它们允许快速实现可定制但复杂的微流体和微针特征。但是，以前报道的3D打印方法利用了昂贵的仪器，而该仪器缺乏在单个步骤中打印两个特征所需的多功能性以及在不同长度范围内渲染组件的吞吐量。在这里，这是文学史上的第一次 我们设计了一种制造方案，可在单个步骤中创建与微流体结构相接的空心微针。我们的方法利用立体光刻3D打印技术，并突破了其界限（实现低于全宽度激光最大半点尺寸分辨率的打印分辨率），从而以比以前报道的方法更低的成本，更高的打印速度和吞吐量创建了复杂的体系结构。为了证明潜在的应用，已打印了支持微流体的微针结构，以在单个设备中进行流体动力混合和透皮药物递送。所提出的架构可以在未来的生物医学设备中采用，以促进用于透皮药物递送应用的新操作模式，例如用于生物治疗的临床前测试的联合治疗。