Collaborative Research: Inkjet Printing Framework by Droplet Impact-induced Ink Release from Liquid Crystal Receiving Substrate

喷墨印刷技术由于其高精度和可再现性而成为广泛使用的制造方法。然而，目前的喷墨印刷技术受到油墨选择有限的限制，并且需要额外的配制步骤来印刷复合材料，这限制了其在工业中的应用。这项资助支持基础研究，旨在创建一种新的喷墨打印方法，将墨水封装在液晶基板中，并最终扩展到更大范围的材料。如果成功，研究成果将使先进材料的打印成为可能，包括用于传感器和可穿戴设备的有机电子产品，并使医疗保健和能源部门受益。推广和教育活动涉及从K-12到本科生的学生，以激发对STEM领域的兴趣，这将培训下一代制造业劳动力，并鼓励代表性不足的群体参与STEM。传统的喷墨印刷需要具有低粘度和高喷射速度的油墨材料用于墨滴的分配。另一方面，低粘度导致液滴飞溅在接收基底上并损害打印分辨率。因此，存在“可印刷”的油墨性质和操作条件的有限组合。这项资助不是将墨滴分配到传统的固体表面上，而是支持旨在了解嵌入液晶膜中的油墨化学品的冲击诱导油墨释放机制的基础研究。在此过程中，使用液滴冲击将油墨释放到液晶表面上，以实现粘性材料的喷墨打印。将进行理论分析以确定液晶膜中嵌入的油墨的受控释放所需的临界条件。将使用实验来确定允许液晶膜的设计和油墨释放的控制的关键参数，以了解韦伯数对油墨释放的影响。如果成功的话，这项研究将使以前难以或不可能打印的材料，如热固性和（半）导电聚合物的厚度和尺寸可控的打印成为可能。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。

Inkjet printing technology is a widely utilized manufacturing method due to its high precision and reproducibility. However, the current inkjet printing technology is restricted by the limited choices of inks and requires additional formulation steps to print composite materials, which limits its applications in industry. This grant supports fundamental research that aims to create a new inkjet printing method to encapsulate ink in a liquid crystal substrate and eventually expands to a larger range of materials. If successful, the research outcomes will enable printing of advanced materials, including organic electronics for sensors and wearable devices, and benefit healthcare and energy sectors. The outreach and education activities involve students ranging from K-12 to undergraduate levels to stimulate interests in STEM fields, which will train the next generation of manufacturing workforce and encourage the participation of underrepresented groups in STEM. Traditional inkjet printing requires ink materials with low viscosity and high ejection speed for the dispensing of ink droplets. On the other hand, low viscosity leads to droplets splashing on the receiving substrate and compromising the print resolution. As a result, there are limited combinations of ink properties and operating conditions that are “printable.” Instead of dispensing the ink droplet onto conventional solid surfaces, this grant supports basic research that aims to understand the impact-induced ink release mechanism for ink chemicals embedded in a liquid crystal film. In this process, the ink is released onto the liquid crystal surface using droplet impacts to enable the inkjet printing of viscous materials. Theoretical analysis will be carried out to identify critical conditions required for the controlled release of the embedded ink in the liquid crystal film. Critical parameters that allow the design of the liquid crystal film and the control of the ink release will be identified using experiments to understand the effects of Weber number on ink release. If successful, this research will enable the printing of materials with controlled thickness and dimensions that were previously difficult or impossible to print, such as thermosetting and (semi)conducting polymers.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.