Capacitive Plants

In one day, we explored turning plants into capacitive sensors.

Using an ATTiny microcontroller with capacitive sensing library, we built a circuit that could be clipped onto plants; the closer another capacitive object got to the plant, the faster the LED would blink.

We started out clipping the circuit to non-organic sensors like aluminum foil and metal cans to discover that surface area positively correlates with sensitivity. As we continued our experiments, we learned the importance of grounding both the to earth, so that both sensors share the same ground.

Experimenting with plants as a capacitive material allowed us to better understand capacitance and basic electronics on the atomic level; dealing with materials that can’t be soldered onto a breadboard was extremely powerful in heightening our awareness of properties of electronics as well as the physical world.

The first four days of the course consisted of multiple explorations, leading up to the final experiment. We explored circuit bending, creating simple circuits out of paper, fabric, and other everyday objects, and thermochromatic (heat-sensitive, color-changing) paint.

This material exploration enhanced our learning of electronic components like transistors and MOSFETs.