Biomimetic adhesion for transfer printing via microstructured surfaces

Demand for robust engineering techniques on the micro and nano scales has been steadily growing in the age of modern technology, not only because of the driving force to fit electronics into smaller form factors, but also for a variety of other applications, from devices with microfluidic functions to components whose interfacial behaviors are key features. In our research we attempted to develop a tool that facilitates assembly of a wide variety of devices on both conventional and novel surfaces in the hopes of both improving modern capabilities of technological fabrication, as well as opening up possibilities for new classes of devices that can be easily assembled on surfaces and in form factors that were not previously possible. In summary, primary benefit of this technology is the potential ability to fabricate a variety of electronic devices on any surface – thus expanding the versatility and ability to integrate different classes of technology in way that is not possible using modern, competing fabrication methods for micro and nano-scale chemical/electronic/mechanical devices. In the first two chapters, I will discuss background information relating to the basis and motivation for this technology, beginning with a summary of adhesion – how different types of adhesion occur and what their applicability is, with a focus on dispersive, or van der Waals adhesion – followed by a discussion of the field of biomimetics and how the study of naturally occurring dry adhesion techniques employed by animals such as geckos and insects has inspired a field of research into the use of dispersive intermolecular forces as an engineering solution for limitations of nanofabrication and assembly. In the following chapters I will describe our own group’s design, fabrication, and iii testing of a variety of microstructured surfaces intended to control adhesive strength by increasing it and decreasing it, as needed. Finally, I will present the results of our experiments and draw conclusions about the effectiveness and future potential of transfer printing via kinetically controlled microstructured stamps