Inspiring a new generation of nanoscientists with a mobile laboratory
Nanotechnology is a growing field that is expected to double in size—in terms of jobs and the number of commercial products—over the next three years.1 A typical high school graduate, however, has no notion of what nanotechnology is, how it is useful, or how they might pursue a career in this field. An even more startling fact is that most high school students have little or no understanding of the nanoscale, and how it differs from microscopic or macroscopic scales. Furthermore, many inner-city schools do not have science laboratories with functioning light microscopes, let alone electron microscopes capable of nanoscale imaging. This situation is leaving vast swaths of the US population uninspired, underprepared, and chronically underrepresented in science and technology occupations.
In efforts to combat this problem, several recent initiatives have been introduced. For example, as part of Hitachi's Learning Labs program, tabletop scanning electron microscopes are being delivered to educational institutions across the United States.2 However, a clearly articulated set of best practices—for introducing the scanning electron microscope (SEM) or the nanoscale to grade-school students—has not yet been created.
To address this issue, we are currently employing a team of trained research scientists to investigate how electron microscopy can be used most effectively in grade-school classrooms.3 We conduct this work on board the BioBus,4 which is a state-of-the-art mobile laboratory run by a team of trained research scientists (see Figure 1). The BioBus is based in New York City and spends every day parked outside a K–12 (i.e., kindergarten to 12th grade) school. Over the course of a day, six classes (of up to 30 students per class) visit the BioBus. All the students who board the BioBus are given a hands-on experience with research-grade microscopes. In addition, all of our lesson plans are developed according to the principles of inquiry-based learning. We find that the students leave with a heightened interest in science. Current thinking in the field of science education categorizes inquiry into four levels, i.e., limited, guided, structured, and open.5, 6 We strive, therefore, to guide students through these different levels of inquiry. In this way, their science learning experience mimics and prepares them for actual research environments. Our goal is to place our students on research and teaching internships at the BioBase (our community science laboratory) or at academic and industry research institutions.
On the BioBus, we inspire students to participate in the various forms of inquiry-based learning by introducing them to Daphnia (a genus of common freshwater crustaceans). Daphnia are only a few millimeters in length and are therefore barely visible with the naked eye. During a typical 45-minute BioBus lesson, however, we show students how to use a stereomicroscope to observe an entire Daphnia body (i.e., limited inquiry). We then prompt the students with a question about the anatomy or behavior of Daphnia. We allow them to use the microscopes as they try to answer this question (i.e., guided/structured inquiry). More often than not, the high-resolution images of Daphnia are so startling to the students that they are provoked to ask their own questions. When this happens, we encourage the students to answer the questions using methods that they devise themselves (i.e., open inquiry).
After we have introduced Daphnia (and the processes of inquiry) to the students with the use of light microscopes, we give them the opportunity to explore the physiology of the organism with our onboard Hitachi TM3030 tabletop SEM. We demonstrate how to operate the SEM so that the Daphnia can be magnified even further. We also show them how to measure the structures that they observe (limited inquiry). The students are then able to select a region of the animal in which they are interested. They can increase the magnification, as required, until they reveal new structures that had previously been invisible (guided/structured inquiry).
Ideally, the BioBus experience acts as a catalyst for new questions that the students can then answer on their own (open inquiry). Indeed, in many cases, the products of our students' inquiries become the subject of inquiry for future students. For example, our library of SEM Daphnia samples was prepared by two students (aged 10 and 15) who participate in a weekly after-school program at the BioBase. The concept of this image library was conceived by the two students after they had been introduced to Daphnia and the SEM via other experiments (i.e., limited inquiry leading to open inquiry). To prepare the Daphnia for imaging, the students performed serial dilutions of the samples in ethanol. They then took the samples to Columbia University where they watched (and participated) in critical point drying and sputter coating processes. They were also able to learn the theory behind these techniques throughout the work (see Figure 2). Once the prepared samples were ready, the students decided to focus on the primary antennae of the Daphnia for further imaging and description (see Figure 3).
Through the BioBus program, we are currently studying how electron microscopy can be used effectively for educational purposes in grade-school classrooms. At present, about 8000 students per year have the chance to use the SEM on board our mobile science laboratory. We believe that our model of using an SEM in K–12 classrooms can—and should—be widely applied. For all these grades, we think that an SEM experience is most powerful when the instrument is used in conjunction with light microscopy and inquiry-based learning. We are continuing to develop our SEM curriculum as part of a collaboration with the Materials Science and Engineering Center at New York University. The goal of this collaboration is to engage students with cutting-edge materials science experiments and researchers. We believe that by introducing students to the world of the nanoscale (by way of the microscale), and by following the best practices of inquiry-based science pedagogy, we will be able to inspire the next generation of nanoscientists.