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Phosphenes: Crafting Resistive Heaters within Thermoreactive Composites

See publication on ACM ↗ thermo-vis repo ↗


Phosphenes aims to expand the design potential of heat as an intuitive creative medium. This design system includes a maker-friendly fabrication tool and pipeline to compose resistive heater artifacts that generate heat spatially and temporally.


Smart dynamic materials have been a popular subject in the last few years. Recently, researchers have designed maker-friendly paper-embedded electronics, and compositions that leverage light as an aesthetic actuator. It’s important to be able to work with these materials to expand our definition of art and on the types of art that can be created, and explore how interactive components can be used within traditional art practices. We were inspired to explore another material—heat and heat-sensitive material (thermochromic pigment). Specifically, our research strives to fit into a larger body of practice—traditional painting.

Since thermochromic pigment is both physical and dynamic (it changes color over time), there is great potential for heat as creative media, especially since it can be generated with various external sources that are not limited to the environment. Whereas light is instant, heat is gradual—you might imagine thermochromes being used to communicate state changes (ex: volume). We aim to invite artists and designers to play with time, space, heat, color, and various actuation sources.

Research through Design

I worked closely with Professor Cesar Torres under Professor Eric Paulos. My aim was to understand how we could most effectively heat up paintings within a minute to reveal the full gradient of color. Lastly, we came up with interaction and composition motifs describing applications for this new medium.

Characterization Experiments

For our characterization experiments, we designed a 4x6 PET sheet of serpentine conductive ink circuits with varying thicknesses. Our goal was to log temperature values and develop heating and cooling formulas based on circuit area, and applied resistance and voltage values, to help us understand heat-up time. Our initial process was to use a hand thermometer, manually logging the temperature at each second. This proved to be unwieldy resulting in human error, so we designed a circuit with a thermistor logging the temperature at each second.

With our data, we came up with two formulas: a heating and cooling curve. With the two formulas, I developed a lightweight tool with React to help us visualize the effect of resistance, area, and voltage of a circuit on heat-up time. With an Adobe Illustrator plugin, we calculate the area of each circuit, and indicate the resistance and voltage values.

Heating Curve Cooling Curve

Studio 2 / Impossible Geometries

Conclusion, future, questions.

Apart from painting, there are many other ways we might utilize this new media. We could apply it in dynamic forms, multi-dimensional forms (in origami). We could experiment with how a painting could cool down (using a Kepler element). We might think about scale.

  1. How might dynamic display design change on the body?
  2. What other design principles might we contribute for supporting this new expressive medium?
  3. Future explorations on technique, material, tool, and practice?