Deformation of Stamp Features with Slanted Walls During Microcontact Printing

F. E. Hizir[1], H. M. Al-Qahtani[1, 2], D. E. Hardt[1]
[1]Massachusetts Institute of Technology, Cambridge, MA, USA
[2]King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia
Published in 2014

Microcontact printing is a method for depositing patterns of thin films or molecular monolayers on surfaces using a polydimethylsiloxane (PDMS) stamp for selective mechanical contact (Figure 1). Undesired deformation of the stamp features during printing affects printed pattern quality. Hence, stamps need to be well-designed to prevent erroneous prints.

Existing investigations identify the collapse modes for deformation of stamp features (Figure 2), develop models for calculating feature stiffness, and reveal the interdependency of these on feature spacing and aspect ratio [1]. Their results are limited to stamp features with straight walls only. However, recent work by Nietner [2] has demonstrated the ability to create micro features with adjustable wall angles.

In this study, deformation simulations are extended to cover the stamp features with slanted walls using the Structural Mechanics Module in COMSOL® software (Figure 3). Work is in progress to obtain stiffness and collapse mode maps for slanted-walled stamp features over a range of experimentally achievable aspect ratio and spacing values.