Brian Simpson

Capture/release ability of thermo-responsive polymer particles

Strain engineering was used to make polymer particles that are able to reversibly alter their geometry from three dimensional tubes to two dimensional layers and consequently alter their properties upon changes in temperature. A bilayer of two dissimilar materials, one being a polymer, was deposited on a sacrificial substrate and polymer tubes were formed due to the release of the interfacial residual stress upon removal of the sacrificial substrate. The bilayer consisted of a polydimethysiloxane (PDMS) film with a thickness of several microns coated with a nanometer-thick gold (Au) film. Alternatively, SiC was used instead of Au to demonstrate that the fabrication method can be applied using any two dissimilar materials. The diameter and length of the resulting polymer tubes can be tuned through the thickness of the bilayer and the processing conditions used. The modulus and geometric characteristics of these polymer particles were also determined. Finally, the ability of using these polymer particles as delivery vesicles was demonstrated through selective capture and controllable release of a fluorescently-labelled polymer such as poly(ethylene glycol), which was adsorbed only on the Au and not the PDMS surface of the polymer particles.

Systematic Design Method for Large-scale Manufacturing of Fabricated Polymers

There is a growing interest in the development of new design methods that will allow companies to adapt to a world that is becoming more competitive due to globalization and a rapidly changing global economic landscape. Several new techniques are being developed as a result of this interest that addresses the unique characteristics of product evolution. For example, Otto and Wood presented a new reverse engineering and redesign methodology that focuses on the process steps needed to understand and represent a current product with the combination of various techniques to address the different stages of the design process [1]. In this paper, we present a case study involving the use of augmentation tools such as affinity diagrams and quality function deployment’s (QDF) house of quality to augment the systematic design approach originally developed by Pahl and Beitz (P&B) [3] and apply it to an existing process and design issue. While presenting their approach, we apply our augmented approach to a laboratory-scaled fabrication process for the creation of adaptive polymer particles. We demonstrate that this augmented design approach could create a large-scale fabrication method that is low in cost, high in quality, and provides greater efficiency than the original method. According to our results, the process time was reduced by as much as 35.4% which would save thousands of dollars each year. In addition, the quality of the fabricated polymeric samples was improved significantly due to the use of advanced tools and simulation techniques. This augmented P&B method will provide an additional option for businesses and engineering designers to consider when faced with the challenges of sustaining designs and design processes.Copyright