Both sponge and salt are now taken as disposable, everyday commodities; often nothing more than a household staple. But salt was once traded as a high-value currency, and sponges, used for cleaning for over 5000 years, were locally harvested rather than synthetic and mass-produced. In Absorb, both sponge and salt regain an essential value.
Absorb turns a mindless, daily routine of wiping things up with a sponge and squeezing it out into the critical mechanism of the lighting system.
Process
I considered two directions: 1) What if the sponge physically absorbs the light? 2) What if the sponge absorbs a liquid to serve as the electrical switch?
For the first direction, I tucked an LED strip into the sponge; its porosity acted as a dimmer. The porous side created a warm, diffused glow. The scrubby side obscured the light too much. Ultimately, the porosity of the sponge was limited to aesthetics, and I wanted to leverage it as a function.
The second hypothesis: the sponge absorbs a liquid to serve as the electrical switch.
The iterative process had three steps: build a standard circuit (4.5V battery, copper wire, a 3.4V bulb, a switch). Replace the switch with aluminum electrodes. Then add the sponge and salt water.
Progressively building the circuit from basic switch to aluminum electrodes to inserted in sponge.
When salt dissolves in water, the sodium and chloride ions become charged particles that can carry current. With aluminum electrodes inserted into a salt-water-soaked sponge, the circuit closes. Squeeze the water out and it breaks.
The first attempt failed to turn on the bulb; there wasn’t enough salt to conduct the electricity. While adding more salt fixed this, the bulb was much dimmer than with direct electrode contact. The salt water had hit saturation; adding more just settled it at the bottom undissolved. Given the time for the workshop, I chose to run with this limitation and note it for future explorations on the system.
Functional constraints between conductivity and gravity became forcing functions of the final design. In my initial design, the electrodes were inserted vertically. Lifting the sponge drained the salt water away from them by gravity, breaking the circuit. By orienting the sponge horizontally, the electrodes stayed submerged enough to conduct the current.
This constraint pushed me to rethink the overall form, establishing the sponge as the base and the aluminum rods as both electrodes and structural elements of the lamp’s arm. The components of the circuit serve both function and structure.
Outcome and future steps
Absorb restores a kind of essential value to both sponge and salt water: not sentimental, but functional. The salt conducts. The sponge absorbs. The system playfully exposes the underlying electrical circuit through how one interacts with the object.
With more time, I'd investigate whether a different, higher concentration electrolyte solution or a sponge with higher-density open-cell foam could improve the conductivity closer to that of the electrodes touching directly , allowing the light to shine brighter.
