CAREER: Conformal Stamp Printing for 3D Curvilinear Electronics Manufacturing

以3D曲线布局构造的电子器件具有许多应用;示例包括集成有传感器的智能接触透镜、来自弯曲图像传感器阵列的宽视场相机以及具有高辐射效率的球形螺旋天线。然而，由于制造技术的差距，创建3D曲线电子产品非常具有挑战性。该学院早期职业发展（CAREER）奖支持基础研究，为3D曲线电子制造开发保形印章打印方法提供所需的知识。由保形压印印刷制成的3D曲线电子器件可用于医疗保健、空间、电信和能源行业。因此，这项研究的成果将有利于美国的经济和社会。该奖项还将支持教育和推广活动，例如为高中学生及其教师提供学习机会，为本科生提供研究经验（特别是来自代表性不足群体的人），以及向市民传播最新的科学和工程知识。印刷保形邮票需要使用一个充气的弹性气球，（保形印模）来拾取电子元件（油墨）并将其打印到曲线表面上以创建3D曲线电子器件。第一个研究目标是建立印模中的变形和诱导应变之间的关系。为了实现这一目标，印模的材料特性，包括应变-应力关系和模量，将通过弹性薄板的拉伸试验来表征。采用测量的属性，基于应变能的分析模型在邮票和有限元模拟下的膨胀邮票变形将被用来预测变形和相关的应变之间的定量关系。第二个目的是量化印章剥离速度对印章和油墨之间的界面粘合强度的影响。为了实现该目的，将基于剥离以使刚性硅（油墨）和粘弹性弹性体（印模）之间的界面破裂时的能量释放率来构建与剥离速度相关的粘附强度的模型。通过实验验证，该模型可用于预测剥离速度对界面结合强度的影响。第三个目标是建立印模的变形与油墨的变形、应变和图案失真之间的关系。为了实现这一目标，将进行印刷期间和之后的变形状态下的油墨的有限元模拟。在实验验证后，利用模拟方法，捕捉印章在不同变形条件下油墨的变形、应变和图案变形。

Electronics constructed in 3D curvilinear layouts have many applications; examples include smart contact lens with sensors integrated, wide field-of-view cameras from curved image sensor arrays, and spherical helix antennas with high radiation efficiency. However, it is very challenging to create 3D curvilinear electronics due to manufacturing technology gaps. This Faculty Early Career Development (CAREER) award supports fundamental research to provide needed knowledge to develop conformal stamp printing approach for 3D curvilinear electronics manufacturing. 3D curvilinear electronics made from conformal stamp printing can be used in healthcare, space, telecommunication, and energy industries. Therefore, outcomes from this research will benefit the U.S. economy and society. The award will also support educational and outreach activities, such as providing learning opportunities to high school students and their teachers, offering research experiences for undergraduate students (especially those from the underrepresented groups), and disseminating the latest science and engineering knowledge to the general public.Conformal stamp printing involves employing an inflated elastomeric balloon (conformal stamp) to pick-up and print electronic components (inks) onto curvilinear surfaces to create 3D curvilinear electronics. The first research objective is to establish the relationship between the deformation and induced strain in the stamp. To achieve this objective, the stamp's material properties, including strain-stress relationship and modulus, will be characterized by tension tests of thin elastomeric sheets. Employing the measured properties, both analytical models based on strain energy in the stamp and finite element simulations of inflated stamp under deformation will be used to predict the quantitative relationship between the deformation and associated strain. The second objective is to quantify the effects of stamp peeling speed on the interfacial adhesion strength between stamp and inks. To achieve this objective, a model of adhesion strength related to peeling speed will be built based on the energy release rate when peeling to crack an interface between rigid silicon (ink) and viscoelastic elastomer (stamp). After being verified by experiments, the model will be used to predict the effects of peeling speed on interfacial adhesion strength. The third objective is to establish the relationship between the deformation of the stamp and the deformation, strain and pattern distortion of the inks. To achieve this objective, finite element simulations of the inks at deformed states during and after printing will be performed. After being verified by experiments, the simulations will be utilized to capture the inks' deformation, strain and pattern distortion with various deformation conditions of the stamp.