Material Testing

I teamed up with Youjin and we tested the variable resistance in materials by using a multimeter. As a general observation, it was a bit hard to get stable value reading. I saw different values recorded from the same material just from different placements of the alligator clips or application of different levels of pressure or stretch. Although the sensing results have fluctuated, it was interesting that conceive varied applications using soft conductive materials. While thinking of applicable materials, I remembered some materials that I had seen at Material Connexion showroom before.

Sensor Sprint

For the sensor sprint, Dan, Anita and I worked out on squishy and stretch sensor. We used the Eeonyx fabric, for the stretch sensor, sewn underneath of the hammock at ITP. Using the multimeter, we were able to measure the resistance when it was stretched by Dan resting in the hammock. We found that the stretch sensing fabric could easily lose the elasticity if it over-stretched, so the consequent sensed value was unstable or even not detected.

For the squishy sensor, we mixed Eeonyx fiber with soft stuff. We placed it under a fabric patch and designed a squishy doll with cute eyes. Maybe we can put some LEDs or sound to make it more interactive later on.

Research Groups

Youjin and I grouped up again. We decided to make a game controller using stretch sensing fabric. The controller was going to be a wooden slingshot and we attempted to play Angry Birds-like web game with it.

The circuit was simple. We interlinked two pieces of fabric, and fetch resistance values from each of it from different levels of stretch. The distance of how far the shot could be reached depends on how much the fabric is stretched. Since we used separated two parts of fabric pieces, we could determine which direction(left or right) that the user wanted to shoot. If the right string stretched, the shot goes left, and vice versa.

We have done fast prototyping in class. Color changing and numbers on the screen indicate the level of stretching(power level of the shot).

Beautiful Sensor – Go Card

For the final, we attempted a kind of interactive educational application with soft sensing. We decided on making acrylic card deck that makes easy to learn Korean letters. Based on the structure of Korean letters, we designed each circuit on letter cards that painted by conductive ink to make every card into really simple but modulized circuit board. For instance, ‘ㄱ / -g- /’ letter card has resistance value around 120, and 160 on ‘ㅏ / -a- /’. So, we presumed that it was able to determine what letter is showing now by indicating resistance value.

Korean Syllable Structure.

We designed first a base circuit to connect the resistors(letter card) in parallel.

After that, we made consonant-vowel letter cards each one of them.

We added sound component so that user can hear the actual voice sound of the assembled letter and can remember it more effectively. As a result, the painted circuits worked pretty fine and were stable as actual resistors.