By Ashok Ajoy, Asst. Professor of Chemistry (All photos courtesy of the Ajoy lab.)
We conceived of a “remote laboratory” experiment during the Fall 2020 semester as a means to give students in Chem 105, the upper division course in instrumental and analytical chemistry, hands-on experience with laboratory equipment amidst the COVID pandemic. The project leaders were research scientists Paul Reshetikhin and Emanuel Druga.
Our goal was to provide every student in the class a small device that we could ship to them and they could build and perform experiments with from the confines of their homes. This would allow them to engage with laboratory equipment while also giving them a flavor of the inner workings of instruments they would come across in future academic or industrial settings.
Fig. X shows the lab “kit” shipped to every student. It consisted of a 6in. cubical box, with a controllable resistive heater. The goal of the experiment was to stabilize the temperature of the box to within 0.2deg C, and elevated 10deg above ambient. Students were meant to accomplish this by setting up a temperature feedback (“PID”) loop. As a result, they were exposed to important concepts in feedback control in the context of temperature, that form a critical component in many laboratory instruments (e.g. gas chromatography). Moreover, through the experiment, the students learned how to interface and control an instrument with a computer through Labview and Python, a skill that is valuable in industry.
Perhaps the biggest draw of the experiment was that the students had to build the devices themselves. Our team designed, constructed, 3D printed, and laser cut the components. The kits also shipped with an Arduino microprocessor and custom made printed circuit boards. These were provided to the students as a laboratory “kit”, which they then had to assemble themselves. We were pleasantly surprised as to the extent the students enjoyed this; after spending several hours on Zoom every day for their other classes, for many students this was there only source of hands-on activity. They even infused their own creativity into the experiment. For example, one student altered the 3D printed parts originally provided with thermoplastic material so that the device changed color as the temperature was altered.
Catering for a relatively large class size (26 students in Fall 2020 and 50 students in Spring 2021) meant that we had to design the devices to be low in cost and relatively easy to be produced en masse. Our final design employed low-cost electronics with custom made printed circuit boards (PCBs) that could be all snapped together with minimal soldering. The central heating component was also produced in a PCB, while the high-performance and low-cost sensors were employed to provide temperature values inside and outside the device. The devices cost ~$100 each and every student in the class had access to a device for several weeks to carry out their experiment from home.
Overall, the feedback from the students in this class was overwhelmingly positive. They enjoyed the chance to engage with an instrument at a deep level, and the experiment fostered a “builder” spirit in them. For many of them the experience was a highlight in an otherwise tumultuous semester.