ERI: Nondestructive in-situ Evaluation of Bio-printed Constructs Using Video-based Vibrometry

生物增材制造（bio-AM）在快速制造高度定制的生物医学设备和植入物方面显示出巨大的前景。然而，bio-AM的一个关键障碍是打印质量大大低于所需的工业标准，部分原因是缺乏有效的原位监测和控制方法来去除缺陷。该工程研究启动（ERI）赠款将支持旨在建立非接触式振动监测的基础研究，以确定生物结构的结构缺陷，因为它们正在制造。该研究成果预计将通过实现生物AM的潜力和加强美国在生物经济中的竞争力，对公共卫生和生物医学领域产生广泛的社会经济影响。综合研究和教育计划，与生物制造和生物技术的国家优先事项相一致，将激发学生对生物制造的兴趣，使本科生和研究生接触生物AM的研究前沿，并培养为生物经济做好准备的下一代劳动力。了解缺陷的形成机制对于制造高质量的生物材料至关重要。大多数现有的生物材料传感方法需要将传感器附着在增材制造部件的表面上。由于生物结构的柔软和重量轻的性质，接触式传感器可能不适合。研究目的是了解非接触式、基于视频的振动测量如何与各种类型的缺陷相关联。研究内容包括三个方面：（1）识别新的基于特征的复合材料损伤指标，包括反映尺寸缺陷和嵌入缺陷的振动特征;（2）建立可靠的数值模型，以了解生物结构的模态特性如何受到工艺条件（如填充模式和常见缺陷）的影响;以及（3）通过基于视频的振动测量法来识别生物打印材料如水凝胶的动态特性。该项目产生的数据将为研究界提供一个基准，以推进生物制造和生物技术的研究。如果成功，这项研究将极大地改善生物AM器官的结构完整性，并增加可用性，最终挽救生命。 基于振动特征的复合材料损伤度量将为缺陷的自动原位评估提供一种新的工具，并可以加速其他领域的传感和分析研究。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Bio-additive manufacturing (bio-AM) has shown great promise for the rapid manufacturing of highly customized biomedical devices and implants. However, one key barrier of bio-AM is that the print quality is substantially below the required industrial standards, partially because of the lack of effective in-situ monitoring and control methods for defect removal. This Engineering Research Initiation (ERI) grant will support basic research that aims to establish non-contact vibration-based monitoring to identify structural defects of bio-constructs as they are being fabricated. The research outcome is expected to create broad socioeconomic impacts on public health and biomedical fields by realizing the potential of bio-AM and strengthening US competitiveness in bioeconomy. The integrated research and educational program, aligned with the national priorities of biomanufacturing and biotechnology, will stimulate student interest in biomanufacturing, expose undergraduate and graduate students to the research frontiers of bio-AM, and develop the next-generation workforce ready for bioeconomy. Understanding the formation mechanism of defects is critical for manufacturing high-quality biomaterials. Most existing sensing methods for biomaterials require that sensors be attached on the surface of additively manufactured parts. Due to the soft and light-weight nature of bio-constructs, contact-type sensors may not be suitable. The research objective is to understand how the non-contact, video-based vibration measurements are correlated with various types of defects. Three research tasks are planned: (1) identifying novel feature-based composite damage metrics that incorporate vibration features reflecting both dimensional and embedded defects; (2) establishing a reliable numerical model to understand how the modal properties of bio-constructs are affected by process conditions such as infill patterns and common defects; and (3) identifying the dynamic properties of bioprinting materials such as hydrogels via video-based vibrometry. The data generated from the project will provide a benchmark for the research community to advance research in biomanufacturing and biotechnology. If successful, this research will tremendously improve the structural integrity of bio-AM organs and increase the availability, ultimately saving lives. The proposed composite damage metrics based on vibration features will provide a new tool for automated in-situ assessment of defects and can accelerate sensing and analytics research in other fields.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.