Direct process feedback in extrusion-based 3D bioprinting
Direct process feedback in extrusion-based 3D bioprinting
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DOI：
10.1088/1758-5090/ab4d97
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发表时间：
2020-01-01
期刊：
影响因子：
9
通讯作者：
Johnson, Amy J. Wagoner
中科院分区：
文献类型：
--
作者：
Armstrong, Ashley A.;Norato, Julian;Johnson, Amy J. Wagoner
基于挤压的生物打印的一个主要限制是缺乏直接的过程控制，这限制了打印结构的准确性和设计复杂性。缺乏直接的过程控制导致许多缺陷，这些缺陷会影响制造结构的功能和力学结果。机器轴的运动不能可靠地用来预测材料的位置，精确的制造需要额外的材料挤压感测。我们提出了一个迭代到迭代的过程监测系统，可以在材料沉积参考框架中直接控制过程。为了制造低尺寸误差的零件，我们将非接触式激光位移扫描仪集成到打印平台中。在使用设计的参考轨迹制造初始打印后，激光扫描仪在零件上移动以测量材料的放置。自定义图像处理算法将激光扫描仪数据与设计的参考轨迹进行比较，以生成误差矢量。为了补偿测量误差，该算法在第二次打印迭代时修改轴参考轨迹。我们在实验平台上实现了原位过程监测和误差补偿技术，以评估系统性能并演示空间材料放置的改进。
A major limitation in extrusion-based bioprinting is the lack of direct process control, which limits the accuracy and design complexity of printed constructs. The lack of direct process control results in a number of defects that can influence the functional and mechanical outcomes of the fabricated structures. The machine axes motion cannot be reliably used to predict material placement, and precise fabrication requires additional sensing of the material extrusion. We present an iteration-to-iteration process monitoring system that enables direct process control in the material deposition reference frame. To fabricate parts with low dimensional errors, we integrate a non-contact laser displacement scanner into the printing platform. After fabrication of the initial print using the as-designed reference trajectory, the laser scanner moves across the part to measure the material placement. A custom image processing algorithm compares the laser scanner data to the as-designed reference trajectory to generate an error vector. To compensate for the measured error, the algorithm modifies the axes reference trajectory for the second print iteration. We implement the in situ process monitoring and error compensation technique on an experimental platform to evaluate system performance and demonstrate improvement in spatial material placement.