EAGER: Rapid Selective Sintering of Metallic Nanoparticles via a Microheater Array

电子行业正在寻找新的制造方法，以满足市场对可定制、重量轻、环境友好、灵活的电子产品的高需求。这一早期概念探索性研究补助金(AGER)奖支持对早期数字化制造方法的探索性研究，这种方法具有巨大的潜力，可以提供快速、可定制、高能效的柔性印刷电子产品制造。独特的微加热器阵列粉末烧结工艺使用一组数字控制的微加热器快速(毫秒级时间尺度)提供用户定义的聚焦热模式，用于在聚合物基板上选择性烧结金属纳米颗粒。该奖项将支持微尺度热传递、质量传递和烧结的基础物理研究，这些基础物理需要将金属纳米颗粒相互结合并将它们附着在柔性衬底上。如果成功，该项目将使微加热器阵列粉末烧结工艺的进一步开发能够提供一种可行的、高速的、可扩展的数字化制造技术，有可能显著降低制造成本并提高印刷质量，而不是现有的印刷电子产品制造方法，如柔性印刷电路和印刷天线。成功实现这一目标将提高该领域行业的竞争力，促进国家繁荣。参与这项研究的学生将获得多物理建模、数字制造、材料和印刷电子等方面的知识和研究能力，从而为先进制造业劳动力提供良好的准备。教育和外联活动将侧重于扩大来自代表性不足群体的学生的参与，并提高对制造业就业机会的认识。本项目的目标是研究金属纳米颗粒油墨通过微尺度热源的直接热传递快速局部加热和烧结的多个潜在物理因素的相互作用，这对于理解印刷电子产品微加热器阵列粉末烧结过程的潜力和局限性至关重要。具体地说，本项目的目标是：a)模拟纳米颗粒悬浮液在毫秒级微加热器的高热下的传热和蒸发的耦合，以确定加工速度限制；b)了解金属纳米颗粒的微尺度传热和烧结动力学之间的相互作用；c)验证加热器诱导热渗透的极限，以确保烧结纳米颗粒与塑料基材的牢固粘附性。在项目成功完成后，经过实验验证的模型将可用于确定最佳处理条件，这些条件可以扩展到整个过程的全数字版本。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。

The electronics industry is searching for new manufacturing methods in order to meet high market demand for customizable, light weight, environmentally friendly, flexible electronics. This EArly-concept Grants for Exploratory Research (EAGER) award supports an exploratory study of an early-stage digital manufacturing method that has significant potential to offer fast, customizable, energy efficient manufacturing of flexible printed electronics. The unique microheater array powder sintering process uses an array of digitally controlled microheaters to rapidly (millisecond time scale) deliver a user-defined focused heat pattern for selective sintering of metallic nanoparticles on polymer substrates. This award will support fundamental research on the underlying physics of microscale heat transfer, mass transfer, and sintering required to bond the metallic nanoparticles to each other and to adhere them to the flexible substrate. If successful, this project will enable further development of the microheater array powder sintering process to provide a viable, high speed, scalable, digital manufacturing technology, with the potential to significantly lower manufacturing costs and improve the printing quality over existing manufacturing methods for printed electronics, such as flexible printed circuits and printed antennas. Successfully achieving this will increase the competitiveness of industries in this field, and advance national prosperity. Students involved in this research will gain knowledge and research capabilities in multi-physics modeling, digital manufacturing, materials, and printed electronics, thus providing excellent preparation for the advanced manufacturing workforce. Education and outreach activities will focus on broadening the participation of students from underrepresented groups and increase awareness of the career opportunities in manufacturing. The objective of this project is to study the interactions of the multiple underlying physics of the rapid localized heating and sintering of metallic nanoparticle based inks via direct heat transfer from a microscale heat source, which is critical for understanding the potential and limitations of the microheater array powdering sintering process for printed electronics. Specifically, this project aims to: a) model the coupling of the heat transfer and the evaporation of the nanoparticle suspension when subjected to intense heat from a microheater in millisecond timescale to identify processing rate limitations; b) understand the interaction between the microscale heat transfer and the sintering kinetics of the metallic nanoparticles; c) verify the limits of heater induced heat penetration to ensure robust adhesion of the sintered nanoparticles to the plastic substrate. Upon successful completion of the project, experimentally validated models will be available for identification of optimal processing conditions that can be extended to a full scale, fully digital version of the process.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.