In this study we present the fabrication of multilayer microneedles with circular obelisk and beveled-circular obelisk geometries, which have potential applications in implantable drug delivery devices. Micro-milling was adopted as an environmental-friendly and cost-effective way to fabricate primary metal microneedle masters. Polylactic acid (PLA) microneedles with sharp tips were then obtained by micromolding followed by oxygen plasma etching and used for preparing polydimethylsiloxane (PDMS) microneedle molds. A spray deposition process was employed for microneedle fabrication to facilitate the formation of multilayer microneedles while helping in maintenance of drug stability. Multilayer microneedles were successfully formed by sequential spraying of poly(lactic-co-glycolic acid) (PLGA) and polyvinylpyrrolidone (PVP) solutions into the mold. The fabricated PLGA-PVP multilayer microneedles penetrated the pig cadaver skin without breakage and released dyes in the skin at different rates, which reveals the potential for implantable microneedles enabling controlled release. Mechanical testing demonstrated that the obelisk-shaped microneedles were mechanically stronger than a pyramid-shaped microneedle and suggested that strong adhesion between PLGA and PVP layers was achieved as well. Structural stability and functionality of a model drug, horseradish peroxidase (HRP), upon spray deposition was examined using circular dichroism (CD) spectroscopy and enzyme activity assay. HRP retained its secondary structure and activity in PVP, whereas HRP in PLGA showed structural changes and reduced activity. Combination of micro-milling and spray deposition would be an attractive way of fabricating drug-containing polymer microneedles with various geometries while reducing prototyping time and process-induced drug instability.
Engineering design decisions have non-trivial implications, and empathic approaches are one way that engineers can understand and translate the perspectives of diverse stakeholders. Prior literature demonstrates that students must develop empathic skills and beliefs that these skills are important to embody empathic approaches in meaningful ways. However, we have limited understanding of the relationship between students' beliefs about the value of empathy in engineering decision making and how they describe their reported use of empathic approaches. We collected qualitative data through interviews with ten undergraduate engineering students in capstone design. We found that our participants espoused a belief that empathic approaches are valuable in engineering design decisions. However, while students considered diverse perspectives when describing how they made design decisions, their reported behaviour during design decisions did not demonstrate translation of their empathic understanding. Based on these findings, we provide recommendations to educators and researchers.
Background: Engineers need to be able to make robust design decisions. Because design is an ill-structured endeavor, design decisions require some combination of rationalistic, intuitive, and empathic approaches. However, engineering education remains largely oriented towards the use of rationalistic approaches. Purpose/Hypothesis: We posit that the persistent gap between the need to leverage diverse approaches to make engineering design decisions and the emphasis on primarily rationalistic approaches in engineering spaces is due, in part, to the beliefs that individuals hold about diverse approaches. Design/Method: We analyzed interview transcripts to identify the beliefs shared by students and by faculty (as individual units of analysis) about rationalistic, intuitive, and empathic approaches to making engineering design decisions, and then we compared the shared beliefs of the two groups. Results: Students and faculty similarly shared a belief that rationalistic approaches are normative in engineering. The two groups also had a common, general belief that empathic approaches are missing in engineering, but they differed in the ways in which they talked about empathic approaches. Finally, the two groups differed in their beliefs about the role of diverse approaches in practice: students believed rationalistic approaches are and should be used most in practice, but faculty believed that rationalistic approaches are inherently limited and therefore require the use of intuitive approaches. Conclusions: We interpret the pervasive belief that engineers are expected to portray their design decision making as primarily rational as a reflection of an unrealistic yet powerful social norm in engineering spaces, which can be understood as a key part of how the exclusive culture of engineering is perpetuated. We see a need to teach explicitly about this social norm in order to disrupt it, and we encourage engineering educators to reflect on how the ways in which their praxis might endorse or reinforce such unrealistic beliefs, either explicitly or implicitly.
Giselle is a graduate student and research associate at The Ohio State University in the Department of Engineering Education, where she is part of the Beliefs in Engineering Research Group (BERG). She earned her B.S. in Mechanical Engineering from Kansas State University. Her experience teaching firstyear engineering students at her previous university ignited her interest in doing research in the field of engineering education. Her current interest broadly encompasses broadening participating in engineering and development of international engineering programs.
Well-structured, de-contextualized problems that can be solved using solely technical approaches remain a large component of the engineering education curriculum. As a result, students may mistakenly believe that all engineering work can be done the same way—without the use of other approaches. Capstone design courses are an established way of exposing undergraduate students to ill-structured design tasks that more realistically reflect engineering practice. Yet, little is known about the influence of their capstone design experiences on their beliefs about how engineering design decisions are made. Our study compared students’ beliefs about four diverse approaches (technical, empathic, guess-based, and experience-based) to making engineering design decisions at the start of their capstone to their beliefs held at the end of their capstone. We conducted and analyzed qualitative transcripts from one-on-one, semi-structured interviews with 17 capstone students. We found little evidence that students’ experience in capstone courses changed their beliefs about diverse approaches to making engineering design decisions. The minimal change that we did find in students’ beliefs was primarily about guess-based approaches, and that change was not uniform amongst the students who did demonstrate change. Our findings point to the resiliency of students’ beliefs about approaches to design decisions throughout an engineering capstone design experience. Therefore, we recommend instructors foster reflexivity within their classrooms to disrupt these limited, normative beliefs about the approaches needed to make engineering design decisions.
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.