University of Illinois Urbana-Champaign

Advanced instrumented stamps for micro transfer printing and novel application areas

Ahmed, Numair

Content Files
AHMED-DISSERTATION-2015.pdf

Permalink

https://hdl.handle.net/2142/88948

Description

Title
Advanced instrumented stamps for micro transfer printing and novel application areas
Author(s)
Ahmed, Numair
Issue Date
2015-09-23
Director of Research (if dissertation) or Advisor (if thesis)
Ferreira, Placid M
Doctoral Committee Chair(s)
Ferreira, Placid M
Committee Member(s)
  • Rogers, John A
  • Kapoor, Shiv G
  • Kim, Seok
Department of Study
Mechanical Sci & Engineering
Discipline
Mechanical Engineering
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Date of Ingest
2016-03-02T19:33:09Z
Keyword(s)
  • Transfer Printing
  • Heterogeneous Integration
  • Piezoelectric Actuation
  • Active Composite
  • Three Dimensional Integration
Abstract
Transfer printing refers to a set of techniques for deterministic assembly of functional micro/nano scale devices into two and three dimensional spatial arrangements. It provides a versatile route for realizing multifunctional heterogeneously integrated systems such as flexible electronics, biocompatible sensing and therapeutic devices, transparent and curved optoelectronic systems etc. Micro-transfer printing is an automated process that implements deterministic micro scale assembly using a molded viscoelastic stamp typically made out of PDMS. The process relies upon the control of adhesion and fracture at the interfaces between the stamp and the devices being assembled to pick up and release them. A widely exploited strategy to achieve variable adhesion from the stamp is to use the rate dependent effects of the viscoelastic stamp material. It is a very versatile process and has been used in the realization of many novel heterogeneously integrated systems. The process has been implemented industrially to assemble ultra-high concentration photovoltaic panels. This body of work presents the development of new stamp technologies to address the challenges associated with increasing parallelism and shortcomings associated with fixed geometry stamps. Starting from the concept of an active composite material with distributed sensing, actuation and compliance tuning, new stamp architectures are developed. These novel stamps replace the compliance of a bulk PDMS stamp with active functional structures with tunable stiffness; without effecting the ability of the stamps to be used for transfer printing. The new stamp architecture enables active monitoring and control of the micro transfer printing process. Using instrumentation to sense deflections/forces at each post allows detection, measurement and compensation of misalignments between the stamp and donor/receiving substrates. Furthermore this information is used to detect pick up and printing errors at individual posts, allowing for error handling to increase process robustness. Moreover the ability to selectively actuate allows to engage/disengage individual posts. This enables new transfer printing modes such as collect and place. Finally results of pilot experiments conducted to test the feasibility of using micro transfer printing in novel application areas are presented.
Graduation Semester
2015-12
Type of Resource
text
Permalink
http://hdl.handle.net/2142/88948
Copyright and License Information
Copyright 2015 Numair Ahmed

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Graduate Dissertations and Theses at Illinois PRIMARY
Graduate Theses and Dissertations at Illinois
Dissertations and Theses - Mechanical Science and Engineering