A Low-Cost Portable Microfluidic Activity for Outreach and Integration into Undergraduate Courses

Introduction:: Microfluidics are an essential element of day to day life and are routinely used for a variety of home tests ranging from pregnancy to COVID-19 (1). However, the small scale of the devices leads to non-intuitive manufacturing and physics principles that can be difficult to both learn and teach. Further, students have difficulty accessing this technology for experiential learning as microfluidics rely on expensive, specialized manufacturing techniques. We have previously shown that a novel multi-layer microfluidic “sticker” activity helps graduate students attain mastery over microscale physics and manufacturing (2). As the graduate students had previous experience with microfluidics, we were curious as to whether undergraduate students with little to no prior experience would derive the same benefit from such an activity in the context of a similar 4000-level course. In addition, while the portability of this activity is conducive to science outreach activities (science fairs, etc.), it was unclear as to whether the participants would derive benefit as the interaction times are much shorter (< 90 mins). Here, we compare and contrast the results of our assessments of these two undergraduate cohorts.

Materials and Methods:: A cohort of 22 students 3 weeks into a 4000-level course were given three separate 1.25 hr sessions to complete the full sticker microfluidic activity on mixers, valves, and droplet generators. A second cohort of 17 undergraduate students were recruited from a general undergraduate population, given a brief ~18-minute video to watch on microfluidic devices fundamentals the day before their assigned activity session, and 1 hour to complete an abridged version of the full microfluidic activity more so focusing on microfluidic mixers. Both cohorts received a detailed handout with instructions on layer-by-layer assembly and fluidic testing. Before and after the activity the students were given the same brief assessment on the physics and manufacturing of microfluidics, and asked to rate their confidence in their answers. All data was evaluated at the 0.05 significance using a paired Wilcoxon signed-rank test.

Results, Conclusions, and Discussions:: Both cohorts were able to build and test the microfluidics for their respective activities (fig a-e). Groups in the secondary cohort with the limited session were able to build their two mixers in as little as 5.5 minutes (fig e). The confidence weighed scores for the pre- and post-assessments showed that the incoming knowledge for both cohorts wasn’t significantly different. While the students that received the full activity significantly outperformed the students completing the partial activity, both groups showed a meaningful knowledge gain in both physics and manufacturing (fig f). Additional data on question by question performance, student feedback, and comparisons to graduate students will be included in the poster.
Our results show that our activity can lead to significant knowledge increases in the context of an outreach activity (90 mins), but that increased time (225 mins) spread over three days in the context of a course triples the average confidence weighted score. Such data can be very useful in setting expectations for outreach activities and also in creating or modifying 4000-level microfluidics courses to include hands-on activities.


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References (Optional): : 1) R. Bogue, Sens. Rev., 2013, vol. 33, no. 4, pp. 300-304.; 2) Delgado et al, BMES 2022