Exploring environments and objects via haptics has always been a natural and intuitive part of the learning process. When we interact with inanimate objects, people, animals etc., we are sensing forces, tactile information and temperature. This information helps us to build a mental image of the object we interact with.
Unfortunately two dimensional interfaces, such as touch screens, limit us to explore completely new environments solely relying on visual feedback. Making it nearly impossible to develop tacit knowledge when using them, therefore they are difficult to learn and to work with.
In my project I strip down these conventional two dimensional interfaces by getting rid of the visual feedback element and replacing it with vibrotactile feedback. I use this artificial blindness to explore new ways of interactions, which don’t rely on any visual handles.
The first experiments I made were focusing on exploring objects only by the sense of touch and understanding the resolution and limits of human haptics.
Ask somebody to place five items in a box, without knowing what they are, try to answer the following two questions:
- What is in it?
- How did you know what was in it?
This kind of exploration is called tactual stereognosis. Tactual (tactile) meaning via the sense of touch. Stereognosis is the mental perception of three dimensionality by the senses, usually in reference to perceiving the form of solid object by touch.
Two-point discrimination test
The two-point discrimination test seeks to determine, for a specific location on the body, the distance between two contact points at the threshold of when they are perceived as a single contact point versus two separate contact points. The three test areas were: tip of the index finger of the dominant hand, inside of the forearm and lower back.
Throughout the process I created various prototypes for trial and error testing. The findings of these tests helped me to develop my ideas further.
Capacitive sensor with force feedback
The capacitive sensor functions as a pressure sensitive button. After a certain threshold is reached whilst pushing down on the aluminum surface, the vibrational motor provides force feedback, imitating the button “click”.
iPhone touch screen with vibrotactile feedback
In this prototype I used my iPhone’s touch screen as the input interface. After modifying it’s case I was able to attach an ERM vibrational motor to it’s back. The touch input functions as a mouse cursor. When moving the cursor over different textures/patters, one can feel the small virtual bumps. For example when scrolling through a block of text, the user can feel each letter passing under their fingers.
Nintendo DS touch screen with vibrotactile feedback
The goal of this prototype was to strip down the input interface to its bare minimum, eliminating any preconceptions, that come with using touch screens of conventional handheld devices. Unfortunately the resistive touch screen of the Nintendo DS did not provide fast and precise response.
Multi-touch interface using OSC
After searching for affordable multitouch input solutions I’ve decided to create my own using an iPad and TouchOSC.
Perception of space and balance using vibrational feedback
I created an alternate version of the ball-in-a-maze puzzle where the players solely rely on their cutaneous and kinesthetic sensing. The gyroscope of an iPad is used to determine the position of the board and a vibrational feedback is sent to the device when the ball hits an obstacle or the wall.
Richard Sennett, The Craftsman Margaret Minsky, Computational haptics Dan Saffer, Microinteractions Golden Kirshna, The Best Interface Is No Interface