Microfabricated Instrumented Composite Stamps for Transfer Printing

2015 ◽  
Vol 3 (2) ◽  
Author(s):  
Numair Ahmed ◽  
John A. Rogers ◽  
Placid M. Ferreira
Keyword(s):  
Vantage Point ◽  
Strain Gauges ◽  
Stretchable Electronics ◽  
Adhesion Forces ◽  
Transfer Printing ◽  
Single Cycle ◽  
Flexible Displays ◽  
Materials Integration ◽  
Substrate Interaction ◽  
Nano Scale

Transfer printing is an emerging process that enables micro- and nano-scale heterogeneous materials integration for applications such as flexible displays, biocompatible sensors, stretchable electronics, and others. It transfers prefabricated micro- and nano-scale functional structures, referred to as “ink,” from growth or fabrication donor substrates to functional receiver substrates using a soft polymeric “stamp,” typically made from polydimethylsiloxane (PDMS) with patterned posts for selectively engaging the ink. In high throughput implementations of the process, where several structures or inks are transferred in a single cycle, the ability to detect contact and monitor localized forces at each post during critical events in the printing process allows for the development of a robust and reliable manufacturing process. It also provides a unique vantage point from which to study fundamental issues and phenomena associated with adhesion and delamination of thin films from a variety of substrate materials. In this paper, we present a new composite stamp design consisting of SU-8 cantilevers instrumented with strain gauges, embedded in a thin film of PDMS patterned with posts, and supported by a backing layer. The fabrication of such a stamp, its testing and calibration are discussed. The use of the instrumented stamp in measuring adhesion forces between silicon and PDMS is demonstrated. New modes of programming the print cycle that monitor forces to control the stamp–substrate interaction are also demonstrated. Finally, a classifier-based approach to detecting failed pick-up or release of the ink is developed and demonstrated to work within a transfer printing cycle.

Adhesion performance study of a novel microstructured stamp for micro transfer printing

Soft Matter ◽  
2021 ◽  
Author(s):  
Cunman Liang ◽  
Fujun Wang ◽  
Zhichen Huo ◽  
Beichao Shi ◽  
Yanling Tian ◽  
...  
Keyword(s):  
Flexible Electronics ◽  
Heterogeneous Materials ◽  
Transfer Printing ◽  
Performance Study ◽  
Materials Integration ◽  
Nano Scale ◽  
Adhesion Performance

Micro transfer printing is an effective method that enables micro/nano-scale heterogeneous materials integration for flexible electronics. As the key component of micro transfer printing equipment, the stamp is adopted to...

Process Performance of Silicon Thin-Film Transfer Using Laser Micro-Transfer Printing

2014 ◽  
Author(s):  
Ala’a Al-okaily ◽  
Placid Ferreira
Keyword(s):  
Process Parameters ◽  
Substrate Material ◽  
Optimal Operation ◽  
Process Performance ◽  
Transfer Printing ◽  
Silicon Thin Film ◽  
Materials Integration ◽  
Operation Conditions ◽  
Fea Model ◽  
Transfer Method

Micro-transfer printing is rapidly emerging as an effective pathway for heterogeneous materials integration. The process transfers pre-fabricated micro- and nano-scale structures, referred to as “ink,” from growth donor substrates to functional receiving substrates. As a non-contact pattern transfer method, Laser Micro-Transfer Printing (LMTP) has been introduced to enhance the capabilities of transfer printing technology to be independent of the receiving substrate material, geometry, and preparation. Using micro fabricated square silicon as inks and polydimethylsiloxane (PDMS) as the stamp material. The previous work on the LMTP process focused on experimentally characterizing and modeling the effects of transferred inks’ sizes and thicknesses, and laser beam powers on the laser-driven delamination process mechanism. In this paper, several studies are conducted to understand the effects of other process parameters such as stamp post dimensions (size and height), PDMS formulation for the stamp, ink-stamp alignment, and the shape of the transferred silicon inks on the LMTP performance and mechanism. The studies are supported by both experimental data for the laser pulse duration required to initiate the delamination, and thermo-mechanical FEA model predictions of the energy stored at the interface’s edges to release the ink (Energy Release Rate (ERR)), stress levels at the delamination crack tip (Stress Intensity Factors (SIFs)), and interfacial temperature. This study, along with previous studies, should help LMTP users to understand the effects of the process parameters on the process performance so as to select optimal operation conditions.

One-Step Selective Adhesive Transfer Printing for Scalable Fabrication of Stretchable Electronics

2018 ◽  
Vol 3 (3) ◽  
pp. 1700264 ◽  
Author(s):  
Peng Peng ◽  
Kang Wu ◽  
Liangxiong Lv ◽  
Chuan Fei Guo ◽  
Zhigang Wu
Keyword(s):  
Stretchable Electronics ◽  
Transfer Printing ◽  
One Step

Characterization of Delamination in Laser Micro Transfer Printing

2013 ◽  
Author(s):  
Ala’a Al-okaily ◽  
Placid Ferreira
Keyword(s):  
High Speed ◽  
Extensive Study ◽  
Transfer Printing ◽  
Power Absorption ◽  
University Of Illinois ◽  
Printing Process ◽  
Nanoscale Structures ◽  
Materials Integration ◽  
The University

Micro transfer printing is rapidly emerging as an effective method for heterogeneous materials integration. It transfers prefabricated micro- and nanoscale structures referred to as ‘inks’, from growth or fabrication donor substrates to functional receiver substrates. Laser Micro Transfer Printing (LMTP) is a laser-driven version of the micro transfer printing process, developed at the University of Illinois to enable non-contact release of the microstructure, thus making the transfer printing process independent of the properties or preparation of the receiving substrate. In this paper, an extensive study is conducted to investigate the capability of the LMTP process. Using square shaped silicon inks and polydimethylsiloxane (PDMS) stamps, and varying the lateral dimensions and thickness of the ink, the power absorption by the ink is measured to estimate the total energy stored in the ink-stamp system to initiate and propagate delamination at the interface. The delamination time for each size and thickness is experimentally observed at different laser beam powers using a high speed camera. Further, an axisymmetric thermo-mechanical FEM is developed to estimate the delamination temperatures at the interface utilizing the delamination time and power absorption for different ink sizes and thickness.

Fabrication of ZnSnO3 based humidity sensor onto arbitrary substrates by micro-Nano scale transfer printing

2016 ◽  
Vol 246 ◽  
pp. 1-8 ◽  
Author(s):  
Shahid Aziz ◽  
Kim Go Bum ◽  
Young Jin Yang ◽  
Bong-Su Yang ◽  
Chul Ung Kang ◽  
...  
Keyword(s):  
Humidity Sensor ◽  
Transfer Printing ◽  
Nano Scale

A Scale-Dependent Model for Multi-Asperity Contact and Friction

2003 ◽  
Vol 125 (4) ◽  
pp. 700-708 ◽  
Author(s):  
George G. Adams ◽  
Sinan Mu¨ftu¨ ◽  
Nazif Mohd Azhar
Keyword(s):  
Real Contact Area ◽  
Asperity Contact ◽  
Adhesion Forces ◽  
Friction Forces ◽  
Dugdale Model ◽  
The Real ◽  
Nano Scale ◽  
Macro Scale ◽  
Asperity Contacts ◽  
Coefficient Versus

As loading forces decrease in applications such as MEMS and NEMS devices, the size of the asperity contacts which comprise the real contact area tend to decrease into the nano scale regime. This reduction in size of the contacts is only partially offset by the nominally increased smoothness of these contacting surfaces. Because the friction force depends on the real area of contact, it is important to understand how the material and topographical properties of surfaces contribute to friction forces at this nano scale. In this investigation, the single asperity nano contact model of Hurtado and Kim is incorporated into a multi-asperity model for contact and friction which includes the effect of asperity adhesion forces using the Maugis-Dugdale model. The model spans the range from nano-scale to micro-scale to macro-scale contacts. Three key dimensionless parameters have been identified which represent combinations of surface roughness measures, Burgers vector length, surface energy, and elastic properties. Results are given for the friction coefficient versus normal force, the normal and friction forces versus separation, and the pull-off force for various values of these key parameters.

Flexible Plastic Liquid Crystal Displays

2001 ◽  
Vol 709 ◽  
Author(s):  
John L. West ◽  
Greg R. Novotny ◽  
Michael R. Fisch ◽  
David Heineman
Keyword(s):  
Liquid Crystal ◽  
Mechanical Performance ◽  
Polymer Networks ◽  
Liquid Crystal Displays ◽  
Full Potential ◽  
Transfer Printing ◽  
Flexible Displays ◽  
Roll To Roll ◽  
Critical Issues ◽  
Printing Techniques

ABSTRACTFlexible plastic liquid crystal displays (LCDs) offer a number of advantages over traditional glass displays. Roll-to-roll manufacturing of such displays makes possible large size, inexpensive displays. While this type of manufacturing is still in the future, here we report solutions of some of the pressing problems needed to achieve this goal. We utilize liquid crystal effects that do not require polarizers and can therefore utilize commercially available, birefringent substrates such as polyesters and polyethylene terephthalate. We achieve excellent optical and mechanical performance of these flexible displays, even when bent, by creating polymer networks and polymer walls that adhere the front and back substrates and maintain uniform spacing between the substrates. Roll-to-roll processing of flexible plastic displays also requires that the photolithographic techniques used to pattern the electrodes on the current glass LCD’s be replaced by printing techniques and the development of techniques to rapidly etch unwanted electrode material. We must also develop and optimize techniques for rapidly forming polymer walls. Here we report methods of patterning ITO electrodes on flexible plastic substrates using conventional wax transfer printing techniques and rapid etching and cleaning techniques. We also report experiments that elucidate the basic science of rapidly forming polymer walls. We combine these new achievements and understanding and demonstrate their utility by fabricating a flexible plastic LCD using techniques compatible with roll-to-roll manufacturing. Finally, we discuss the critical issues that must be addressed if flexible plastic LCD’s are to reach their full potential.

A Nano-Scale Multi-Asperity Model for Contact and Friction

2002 ◽  
Author(s):  
George G. Adams ◽  
Sinan Mu¨ftu¨ ◽  
Nazif Mohd Azhar
Keyword(s):  
Normal Force ◽  
Real Contact Area ◽  
Adhesion Forces ◽  
Friction Forces ◽  
Dugdale Model ◽  
Single Asperity ◽  
Nano Scale ◽  
Macro Scale ◽  
Asperity Contacts ◽  
Asperity Model

As surfaces become smoother and loading forces decrease in applications such as MEMS and NEMS devices, the asperity contacts which comprise the real contact area will continue to decrease into the nano scale regime. Thus it becomes important to understand how the material and topographical properties of surfaces contribute to measured friction forces at this nano scale. We have incorporated the single asperity nano contact model of Hurtado and Kim into a multi-asperity model for contact and friction which includes the effect of asperity adhesion forces using the Maugis-Dugdale model. Our model spans the range from nano-scale to micro-scale to macro-scale contacts. We have identified three key dimensionless parameters representing combinations of surface roughness measures, Burgers vector length, surface energy, and elastic modulus. Results are given for the normal and friction forces vs. separation, and for the friction coefficient vs. normal force for various values of these key parameters.

Sign in / Sign up

Export Citation Format

Share Document