Project Journal #3 – Soma Garden


SOMA GARDEN is a digital garden powered by your bio data. The sweatier your palms, the more plants and flowers grow. By using electro-dermal activity(EDA) measured using DIY sensors and an Arduino, the changes in a person’s skin sweat glands cause changes in electrical resistance in the circuit which will trigger different levels of animations on the dome’s walls.

Ideation & reflecting:

I wanted to create a project that would treat biofeedback about sweaty palms in a positive way. For a lot of people, sweaty palms are a cause of anxiety as sweaty palms are normally viewed negatively in society. My project prompts personal self-reflection as instead of presenting data to show whether the body is under stress whether emotional or physical, it leverages the neutral nature of plants thus taking away any negative connotations.

Transferring authority of interpreting biofeedback back to the individual:

The animations allow anyone interacting with the SOMA GARDEN to interpret the volume of plants and flowers growing in their own way thus transferring authority on interpreting the bio data back to the user. As a developer, my role in the interpreting is minimal and doesn’t add any connotations either positive or negative to the final result because I focused on quantifying the sweatiness of one’s hands and creating different states for the dome; 0 – 20 (not very sweaty), 20 – 60 (slightly moist), 60-120 (sweaty), >120 (very sweaty)

How it works:

The dome responds to different states according to the sensor value ranges:

0 -(no interaction)

Dome’s walls go white / clear

0 – 20 (not very sweaty)

Animation of grass blades swaying in a breeze. 1/4 height

20 – 60 (slightly moist)

Grass blades swaying, flowers growing to half the dome’s height

60 – 120 ( sweaty)

Grass blades swaying, flowers growing to 3/4’s of the dome’s height

> 120 (very sweaty)

Whole dome fills with flowers and plants

Aesthetic visuals instead of biofeedback as numbers, maintains ambiguity so that individual interprets visuals by themselves:

The idea to grow plants came from the notion that sweating means our bodies are losing water  and that “water is life” and plants need water to grow.









Test run results:


To realize this low-fidelity prototype the following materials are needed:

  • Arduino Genuino Micro
  • Jumper cables
  • 2 Alligator clips
  • Aluminium foil
  • Tape or glue
  • Cardstock and writing implements
  • Scissor or cutting tool & cutting mat
  • 10K resistor
  • Breadboard

Circuit Diagram : source

DIY Polygraph

The grey wires in the fritzing diagram represent the sensors. They are connected to analog PIN A0 on the Arduino board.

To create your sensors – follow the instructions here and design the sensors according to whatever your idea is. This article presents instructions for a sensor to be attached around one’s fingers. For my idea, I envisioned having a pad with a palm cut out so that an individual is invited to place their hand on it. The sensors would be on the tips of two of the fingers. Below are images from my steps of creating the sensors.



Design of a high-fidelity prototype:



For a proof of concept I would like to work on creating this dome idea but on a single screen or panel hanging on a wall. The palm rest with the sensors would be placed beside it. I would like to explore perhaps using Google Glass so that the individual can still be immersed in the SOMA GARDEN. I believe having the individual enclosed gives them space to actually reflect in private on what they are seeing and what it might mean to them.  I believe that this design also gives the individual space to determine what their sweaty palms may mean, perhaps if they are feeling anxious the growing plants may distract them enough so that they can calm down and in terms of personal motivations, they can use the SOMA GARDEN as a space to meditate without external pressure.


Dream design:

SOMA Garden high fidelity idea


When coming up with threshold values test the sensors at different times of the day to get a variety in bio data. Additionally test with multiple individuals to get a more reliable sense of what kind of values you might get back.

Test different resistors to get one that suits your needs. Preferably choose a resistor that generates higher values or allows for a wider range of values on the serial monitor. This will help when creating different thresholds for the sensors. For this project a 330 ohms, 1.oK ohms and 10K ohms resistor were tested and a 10K resistor was chosen. Below are screenshots of readings from the testing of the resistors in the circuit.



Galvanic Skin Response Powered by Arduino (note: the circuit diagram shown in this article is incorrect) : here

Detect Lies with Tin Foil, Wire and Arduino : here


Roof Glass Dome: here

Potted plant: here