Intangible Interaction

Week 1

This week I worked with Peiyu Eva Zhou, investigating sensors. I enjoyed working with her, and felt that we worked well as a team trying to uncover the mysteries of the Dyson Airblade V. We thought the hand dryer was the most interesting appliance in the bathroom because the others had more obvious sensors. The design is so sleek that it doesn’t give away how it works or even what it is at first glance. The sensor activates when you put your hands underneath and the air comes out of a very thin slit in the body. We experimented with putting our hands in different spots to see where the sensor was and it was clear that whatever type of sensor it was it must be detecting hands through the metal. We dug deep into the internet to try to figure out what type of sensor it was. There was a lot of information about the motor that made the air blowing so powerful but not much about the sensor. We eventually found something that said it was a capacity sensor. This relies on detection of objects instead of motion, so as long as we held our hands there, the blower kept blowing. A capacity sensor can also sense objects through the metal which allows the sensor to be tucked inside, leaving less crevices for bacteria to hide.

Here’s our analysis of the interactions between human and hand dryer. We had to guess how the dryer really operated based on our experience with it, so this may not reflect reality. We decided that whether the dryer was blowing or not blowing depended only on whether an object was detected, because it didn’t seem like the dryer turned off after a specific amount of time. The literature on the dryer said that it could fully dry hands in 12 seconds. We held our hands under the sensor for over 25 seconds and it never stopped, so if it does time out, it takes a long time to do so.