A new process, decoupled functional imprint lithography (D-FIL), is presented for fabricating low elastic modulus polymeric nanocarriers possessing Young's modulus of bulk material as low as sub-1 MPa. This method is employed to fabricate sub-50 nm diameter cylinders with >3:1 aspect ratio and other challenging shapes from low elastic modulus polymers such as N-isopropylacrylamide (NIPAM) and poly(ethylene glycol) di-acrylate (PEGDA), possessing Young's modulus of bulk material <10 MPa which is cannot otherwise be imprinted in similar size and pitch using existing imprint techniques. Standard imprint lithography polymers have Young's modulus >1 GPa, and so these polymers used in nanocarrier fabrication in comparison have very low elastic modulus. Monodispersed, shape- and size-specific nanocarriers composed of NIPAM with material elastic modulus of <1 MPa have been fabricated and show thermal responsive behavior at the lower critical solubility temperature (LCST) of ∼32 °C. In addition, re-entrant shaped nanocarriers composed of PEGDA with elastic modulus <10 MPa are also fabricated. Nanocarriers fabricated from PEGDA are shown with model imaging agent and anticancer drug (Doxorubicin) encapsulated in as small as 50 nm cylindrical nanocarriers.
Recent research has investigated methods based on design-by-analogy meant to enhance concept generation. While these analogies can be developed in different ways and can come from many different areas, one of the most common methods is to use key customer needs or key functions as the starting point. One approach uses these key terms to seed a search for grammatically similar words. While these methods are promising, they can be cumbersome and difficult to apply in engineering classrooms or industrial product development settings. This paper presents further evaluation of the Analogy Seeded Mind-Maps method, a new method to prompt generation of analogous solution principles drawn from multiple analogical domains. We randomly select a set of 10–15 words from a graph of grammatically analogical synonyms of a functional design requirement “seed” and populate the first-level nodes of a mind-map with the selected textual analogies. This mind-map then serves as a visual tool that is utilized during the concept generation process. The effectiveness of the tool in generating concepts has been evaluated in previous studies. In the current study, we evaluate the effect of substituting pictures for the verbal analogies in the Analogy Seeded Mind-Maps method. The study involved student volunteers who were recruited from a senior-level design methodology course. The students were asked to complete a simple concept generation task (in teams) using either a purely verbal version of the Analogy Seeded Mind-Maps method or the alternative version that relied on pictorial analogies. The results were evaluated for quantity, quality and novelty of the concepts generated using the two methods. Analysis of the results shows that there is a statistically significant difference in the novelty of ideas generated by the two methods, with the pictorial version producing a larger number of novel ideas than the purely verbal version. While the differences in quantity and quality are not statistically significant at the P-Value < 0.05 level, there are differences that approach this level of statistical significance. Further studies are needed to determine if there is any benefit to a method that combines both verbal and pictorial analogies.
design and geometry modeling for design. Dr. Crawford's research interests span topics in computeraided mechanical design and design theory and methodology. Dr. Crawford is co-founder of the DTEACh program, a "Design Technology" program for K-12, and is active on the faculty of the UTeachEngineering program that seeks to educate teachers of high school engineering. Recent research has investigated methods based on design-by-analogy meant to enhance concept generation. While these methods are promising, they can be cumbersome and difficult to apply in engineering classrooms. This paper presents Analogy Seeded Mind-Maps, a new method to prompt generation of analogous solution principles drawn from multiple analogical domains. The method begins with identifying a primary functional design requirement such as "eject part." We then use this functional requirement "seed" to generate a WordTree, which is a graph of grammatically analogical synonyms. We randomly select a set of 10-15 words from each WordTree list and use the resulting word list to populate the first-level nodes of a mind-map, with the functional requirement seed as the central hub. The word list and resulting mind-map then serve as visual tools that are utilized during the concept generation process. The effectiveness of the tool in generating concepts has been evaluated in separate studies utilizing student design teams working on a wide variety of projects in both the United States Air Force Academy (USAFA), a small academic community, and at The University of Texas at Austin, a large public research university setting. In our evaluation of the method, designers first used the word list (10-15 words from WordTree) to individually generate solutions and then performed team concept generation using the analogically seeded mind-map. The total quantity of concepts was measured. Additionally, the effect of word familiarity and the number of definitions of word were investigated for their effect on the quantity of concepts generated. It was found that the Analogy Seeded Mind-Map method allowed students to generate a large number of concepts in a relatively short amount of time with only brief introduction and explanation of the method. Introduction and MotivationInnovation is often a primary goal during the engineering design process. Various concept generation techniques exist to help designers develop innovative solutions. Techniques such as Brainstorming, 6-3-5/C-sketch and TRIZ 8 , are widely used in the engineering classroom environment. Brainstorming and 6-3-5/C-sketch require the designer to spontaneously generate ideas, but also allow for inspiration from ideas of other participants. TRIZ, on the other hand, provides a more guided approach to solving engineering problems based on addressing conflicts between competing performance parameters. One area of recent interest in concept generation research is the phenomenon of design-by-analogy. The invention of Velcro ® is one of the most popular anecdotes citing the spontaneous use of analogy to solve an...
Recent research has investigated methods based on design-by-analogy meant to enhance concept generation. This paper presents Analogy Seeded Mind-Maps, a new method to prompt generation of analogous solution principles drawn from multiple analogical domains. The method was evaluated in two separate design studies using senior engineering students. The method begins with identifying a primary functional design requirement such as “eject part.” We used this functional requirement “seed” to generate a WordTree of grammatically analogical words for each design team. We randomly selected a set of words from each WordTree list with varying lexical “distances” from the seed word, and used them to populate the first-level nodes of a mind-map, with the functional requirement seed as the central hub. Design team members first used the word list to individually generate solutions and then performed team concept generation using the analogically seeded mind-map. Quantity and uniqueness of the resulting verbal solution principles were evaluated. The solution principles were further analyzed to determine if the lexical “distance” from the seed word had an effect on the evaluated design metrics. The results of this study show Analogy Seeded Mind-Maps to be useful tool in generating analogous solutions for engineering design problems.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.