A Hands-On Approach to Teaching K-12 Students About Microfluidic Devices (Work in Progress)

There have been significant advances with microfluidic devices and lab-on-a-chip technology leading to micro total analysis systems (μTAS) capable of analysis and discoveries in the laboratory, the field, and the clinic. Unfortunately, while the academic community is well versed in the utility and application of these devices, the public (especially promising young scientists) is relatively unaware of their existence. Furthermore, several of the underlying chemical and physical principles governing microfluidics have applications in a several STEM disciplines including engineering, chemistry, physics, and biology. Here, we highlight a series of workshops and outreach activities designed to provide elementary, middle, and high school students an opportunity to learn more about microfluidic devices through a hands-on approach. Initially, these workshops were given to high school students from traditionally underrepresented minorities as part of two week-long summer camp offered by the College of Engineering at Louisiana State University entitled REHAMS and XCITE. The demonstrations provided students with an overview of microfluidics including introductions to polymer chemistry and fluid flow dynamics. The students were able to fabricate and test their own devices using a simple microfluidic gradient generator to mix yellow and blue colored water to make green. Expanding upon these initial demonstrations, we have developed a series of outreach activities to be performed at local area elementary, middle, and high schools focusing on the use of microfluidic droplet generators as tools for cancer diagnostics. The presentations and demonstrations were adjusted depending upon the age range, but all session contained several hands-on activities to show the students what could be done in a few millimeters on a microfluidic device. To show the students what was happening in the device, we constructed large-scale version of the devices for the students to use and experiment with (e.g., a table-top microfluidic droplet trap array that uses ping pong instead of picoliter-sized aqueous droplets). Additionally, a key strength of this outreach program is the inclusion of undergraduate students from the Society of Peer Mentors at Louisiana State University as presenters to increase student engagement. As this work is preliminary in nature and no precise quantitative data has been collected about the workshops, informal discussions with student participants have all been positive with many students appearing eager to learn more about this exciting field of science and engineering Introduction The development of novel microfluidic devices has made a significant impact on the scientific community. These devices take advantage of their small size, laminar flow, and a low surface-tovolume ratio to achieve an unprecedented degree of control over the physical and chemical environment. This technology was initially confined to the manipulation and mixing of two different chemicals in the form of gradient generators; however several advances and new devices have been developed in recent years that provide numerous applications in the fields of human health, energy, and the environment. Moreover, microfluidic devices offer significant advantages of competing technologies due to reduced reagent costs, ease-of-use, significant reproducibility, compatibility with most types of fluorescent microscopy, and a relative degree of biological inertness [1, 2]. By integrating several different types of microfluidic devices into a single chip, researchers have developed micro total analysis systems (μTAS) that allow for fundamental and applied advances in a number of research fields and STEM disciplines. Fundamental devices, including organs-on-chip, provide a realistic environment analogous to different types of human tissue including the heart, lungs, kidneys, and the colon. These systems have been used to assess cellular interactions, angiogenesis, drug effectiveness, and graft-versushost disease [3]. Applied microfluidic technologies are being developed to aid in the fields of personalized medicine and disease diagnostics (both in the clinic and in the field). Yet, even with all of these advances and possibilities, the development and use of this technology is not well disseminated to the general public, especially young scientists. When most K-12 students are asked to come up with a definition for lab-on-a-chip technologies or microfluidic devices, most students think they have something to do with computers and/or smart phones. Moreover, many of these same students are shocked to learn how these technologies, with mostly biological/biomedical applications, are developed by engineers and chemists. The success of microfluidic technology requires the expertise in a number of STEM disciplines including chemical, biomedical, electrical, or mechanical engineering in addition to chemistry, biology, and physics. Many research teams that develop these devices include one or more experts in these fields. This interdisciplinary nature provides a unique outreach opportunity for K-12 students as the students can see applications and learn about core topics in a number of disciplines. Moreover, in the state of Louisiana, chemical engineering is largely associated with the petrochemical industry, thus most K-12 students believe that the only thing that an engineer or chemist can do is to work in the oil & gas industry. Due to all of these factors, we set out to develop two of outreach activities, specifically geared towards K-12 students interested in STEM disciplines, to educate and engage students on the applications of microfluidics and the underlying chemical, physical, and biological phenomena involved in their design and use. This paper deals with our ongoing efforts to develop this set of outreach activities and hands-on demonstrations, which have initially been met with increased student interest and engagement. The first demonstration was held as part of a week-long engineering camp at Louisiana State University specifically designed to increase enrollment of traditionally underrepresented minorities in STEM disciplines. Based on the initial success of these demos, we next developed a more hands-on, personalized activity to educate K-12 students not only about microfluidic devices, but also their use in the field on cancer diagnostics. This second type of activity (which just debuted in the last week of January 2016) was designed for both large-scale STEM nights as well as small classroom activities. A key strength of all of the outreach programs performed thus far is the involvement of current chemical engineering undergraduate students at our university as mentors and leaders. These students, many of whom perform undergraduate research in the field of microfluidics, provide additional guidance and instruction during the demos and activities. Ultimately, it is our intent for these activities to ignite a passion in the K-12 students to one-day enroll in STEM disciplines and continue to make a significant impact in the scientific community. Microfluidics 101: How to teach K-12 students about microfluidics in a 90 minute lecture. The college of engineering at Louisiana State University has three week-long summer camps offered to both middleand high school students to increase interest and enrollment in STEM majors when the students ultimately decide to attend college. These programs are called REHAMS, XCITE, and Project NJneer and provide the students with a chance to live in a university setting and experience all of the engineering majors offered at Louisiana State University. During the program, students are mentored by counselors (current engineering undergraduate students), participate in team-building activities, and are able to attend a 90 minutes lecture given by select faculty from each of the engineering disciplines. During the summers of 2014 and 2015, we were asked to give a 90 minute lecture on chemical engineering. Instead of just talking about the petrochemical industry, it was decided to spend more time giving the students an overview of microfluidics as it has applications not only in the petrochemical industry, but also in the fields of human health and the environment. Additionally, the development of the devices require knowledge of several aspects of numerous STEM disciplines. The demonstration was designed to include both lecture and activity components combined with utilizing active learning techniques such as TAPPS and think-pair-share to increase student involvement and retention. Undergraduate chemical engineering students working in the field of microfluidics were asked to participate in the demonstration to assist in the generation of the session materials and to act as helpers during the delivery of the session. This allowed for more direct interaction and instruction of the camp attendees. The overall goal of the session was to have the students make and test their own microfluidic device. In an attempt to simplify the demonstration, we decided to have the students work with an established microfluidic device called a serpentine gradient generator. This device, which was developed almost two decades ago by Prof. George Whitesides at Harvard University [4], allows for the small-scale mixing of two aqueous streams by length-scale diffusion (Figure 1A). This device requires little in the amount of optimization, can produce an immediate change in output by adjusting the input parameters, and is currently being incorporated into μTAS devices to study numerous biological phenomena including cell migration, drug resistance, and algal biofuels [5, 6]. The length scales necessary for complete mixing of the two inputs are achieved by the continuous mixing and splitting of the channels, which have been patterned in ‘switch-back’ serpentine channels. The seven resultant channels are merged in a final main outlet channel which result