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

喷墨打印技术具有精度高、重复性好等优点，是一种应用广泛的制造方法。然而，目前的喷墨打印技术受到油墨选择有限的限制，打印复合材料需要额外的配方步骤，这限制了其在工业上的应用。这笔赠款支持基础研究，旨在创造一种新的喷墨打印方法，将墨水封装在液晶基板上，并最终扩展到更广泛的材料。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行业受益。外展和教育活动涉及从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。传统的喷墨打印需要低粘度和高喷射速度的墨水材料来分配墨滴。另一方面，低粘度会导致液滴飞溅在接收基板上，并影响打印分辨率。因此，墨水特性和操作条件的组合是有限的，它们是“可打印的”。这笔赠款不是将墨滴分配到传统的固体表面，而是支持旨在了解嵌入液晶膜的墨水化学物质的冲击诱导墨水释放机制的基础研究。在这一过程中，墨水通过液滴撞击释放到液晶表面，以实现粘性材料的喷墨打印。将进行理论分析，以确定在液晶膜中控制释放嵌入墨水所需的临界条件。将通过实验确定允许设计液晶薄膜和控制墨水释放的关键参数，以了解韦伯数对墨水释放的影响。如果成功，这项研究将能够打印以前难以或不可能打印的厚度和尺寸可控的材料，如热固性聚合物和(半)导电聚合物。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.