What I want to do
Use the coqui as a way to teach kids about how they can find their own scientific methods to investigate the world around them
Plug into a wider concept of leadership and how to take action on local environmental concerns.
- Replicate the Coqui Activity
My attempt and results
This was a collaborative effort with two other environmental educators. We attempted to replicate the coqui activity, modified to work in a 2 hour timespan. The activity is great, and clear! If I were doing it again, I would have also read Don Blair's original activity for more information: https://publiclab.org/notes/donblair/09-30-2014/coqui-bbv1-0
- First, we created a list of instructions from the activity, and provided a copy of those to each group. We also drew a big picture of the circuit diagram.
- Our breadboards didn't have nice Vcc or Ground sections like those pictured in the activity, so we decided to use one row of pins at the top of the board as Vcc and a row at the bottom as the ground.
- Instead of screws, we used paperclips through the bottle caps. They were super effective! Sports drinks (like gatorade and powerade) were used preferentially due to their larger caps and larger bottles.
- We had just enough time to introduce, build, and troubleshoot the coqui with the photodiode, and then switch it out for the DIY conductivity cell in our 2 hours.
- The battery cases were tricky to get batteries back out of. I used a pen.
Environmental Education Outline
For my lesson (teaching 8 teenagers and one volunteer) I decided to focus on bigger picture issues of leadership and science rather than dive into the nitty-gritty of the technology.
We started with a brainstorm of what the words "Environmental Leadership" meant, both together and separately. The participants then wrote and shared "Why" environmental leadership was important to them, and "How" they could accomplish it (using a lot of the examples they came up in their brainstorm). Then we moved onto the "What" of the lesson -- measuring water pollution with the coqui.
We talked about how de-ionized water doesn't conduct electricity, because there's no path through the water that electrons can take. However, when there's "stuff" in the water that can conduct electricity, there is a path. Particularly if the "stuff" is something like salt. (I drew the chemical structure of Na+Cl- so the participants could see how it could dissolve in water, and handwave how electrons could flow between them.
I shared how I was curious about road salt in my community, and searched on the internet to find if there was a way to measure it, and found public lab (which is a simplified version of the true story). The coqui is an example of DIY science that can let us find answers to our own questions about environmental problems.
Building the Coqui
We then built the coqui, in pairs. I warned participants to wait until the end to put the batteries into the enclosure (having slightly shocked myself when testing it out) Participants were challenged by this instruction, as putting the batteries in is the most recognizable part of the coqui. Participants were also challenged by the "row 1" and "row 2" portions of the instructions, but these were good challenges that they were able to overcome using the circuit diagram and each other as resources.
Here's how we did it.
- Participants had cardboard cutouts to serve as their "desk" to keep all components on, while working on this outside. These cardboard slates were also used as backs for writing on paper earlier.
- Each individual component (breadboard, capacitor, photodiode, etc.) was passed out to each group one at a time, so they knew what they were, and so I knew that each group had received a complete set. I would ask for the complete set back at the end. I heard from my coworkers that a previous group had walked away with some of the parts (one capacitor and one photodiode) and I wanted to prevent this
- I explained how the breadboard worked (pins in each row are connected to each other, the columns are independent, we're re-creating the circuit diagram)
- I asked them "Do you think this will work the first time?" (A: No) so expect to take time going back through the instructions afterwards to troubleshoot it
- The step-by-step instructions were passed out, and the participants got started
- Once a group got it working, they walked around letting different amounts of ambient light trip the sensor
- An interesting side experiment was using the coqui as a hearing test -- the teens could hear much higher frequencies than I could
- Once they were tired of experimenting with the diode, I asked the successful groups to help me troubleshoot with the groups still in progress. (We were eventually able to get all-but-one group to successfully build their coqui. I still have to troubleshoot that last kit...)
- I asked one group to switch out their photodiode with the conductivity cell and try measuring 3 previously-collected water samples with it, and try to figure out what they were. I didn't tell them, but one was tap water, one was salt dissolved in tap water, and one was lake water
- In the remaining 15 minutes, I asked them to gather around and make their final guesses as to which water sample was which. I then revealed the answer and asked if it made sense. (They could tell lake water from the color, but they thought the high-pitched one was tap water, and the other low-pitched one was polluted water of some kind). I asked them what else they could think of to measure, and how they would be able to use this
- As a reflection, the participants wrote one specific thing they had fun doing, and one thing they learned.
Questions and next steps
- Keep the 555 timer attached to the breadboard when not in use. This keeps it in good condition
- Troubleshoot the kit that didn't work
- Post pictures of the instructions we made
- Order some replacement parts from digikey, mouser, etc.,
Why I'm interested
- I wanted to see if the coqui could make sense in a context of noticing things in your local environment you're curious about, and finding resources online (for example, at public lab) that help you measure these things, and then feel empowered to take some kind of action with that information
- I hope these kids will remember this experience and build upon it later in their lives.
Photos (they were all so huge!):