Through a series of class projects, I’ve explored how plants can act as sensors as well as how we can use sensors to learn about their state.
First, I explored this in a project called Plantastic where I used a swept capacitive frequency sensing circuit to sense touch interactions with a watercress plant (directly based on the work of Touché: Enhancing Touch Interaction on Humans, Screens, Liquids, and Everyday Objects from Disney Research).
I created 4 interactions with my plant that corresponded to the opening of 4 displays on my laptop. Light touch/tap - watercress info page, pinch - pictures of plant growth, full hand caress/pet - recipes using watercress, and last, dipping a finger into the water - last watered date.
In another project called Green Thumb, I explored various basic sensors that can be used to determine if a plant is getting enough water, humidity, and light. These were all connected to a microcontroller with an OLED display and BLE. A phone could ping the device to retrieve sensor data in addition to reading it off the OLED display.