Paper Reading #4: Shape-changing mobiles: tapering in two-dimensional deformational displays in mobile phones

Comments
Joe Cabrera
Derek Landini


Reference Information
Title: Shape-changing mobiles: tapering in two-dimensional deformational 
        displays in mobile phones
Authors: Fabian Hemmert, Deutsche Telekom Laboratories, Berlin,  Germany
              Josefine Zeipelt, Deutsche Telekom Laboratories, Berlin,  Germany
              Susann Hamann, Deutsche Telekom Laboratories, Berlin,  Germany
              Gesche Joost, Deutsche Telekom Laboratories, Berlin,  Germany
              Matthias Lowe, Deutsche Telekom Laboratories, Berlin,  Germany
Presentation Venue: CHI 2010: 28th ACM Conference on Human Factors in Computing Systems;
Date: April 10-15, 2010;
Location: Atlanta, GA, USA

Summary

This paper presents a haptic actuation system for mobile phones: Two-dimensional tapering through an actuated back plate. It suggests two-dimensional shape change could be a suitable addition to existing mobile solutions in implementing an embodied interaction.
After giving an introduction to the subject, the authors give a series of works where shape-change has been explored:

• Extended Actuation: A knob that extends from the phone's side for input, and displays information
• Surface Actuation: Horev's Tactophone which investigates surface change-based displays, & others...
• Angle Actuation: "Talking to the Hand project", an external hard disk that displays synchronization    levels through a twist in its chassis    

For their project, the authors built two prototypes: a shape-shifting mobile phone box, and  a weight-shifting shaped-box. The shape-shifting mobile box is actuated by four servos, that are situated at each corner of the box. This results in a tilt movement of the back plate around two rotational axes. With this configuration, they are able to change the angular properties of the device, as well as the device's thickness.

In order to assess how precise users would be able to determine the angle between the device's front plate and back plate, 12 users participated in a study. The way the study worked is that users had to estimate a series of 15 pseudo-randomized tilt positions while wearing headphones and operating through a curtain. They did this only after having been introduced to the minimum and maximum x, y tilt angles. The same tests were also conducted with a weight-shifting mobile. At the end, a questionnaire was given, and interviews conducted in order to evaluate preferences.

The tests reveal users were able to determine the angle of the back plate with an average error of 5.46 degrees on the x axis, and 5.47 degrees on the y axis. The average time for assessment was 7.01s. The questionnaire revealed an attraction to the shape-shifting mobile as opposed to the weight-shift solution. Even when misjudging the X and Y positions, tilt angles were still estimated correctly.
The authors go on to propose shape shifting as a method of information display.

One thing that is highlighted by the authors is the fact that the users involved in the study did not hold the phone while it was changing shape so that may influence the user's experience in a real world implementation.

Discussion

I was already familiar with this project. I had watched a presentation from the TED conference.The research is still in its infancy however could prove fun, and a novel way of human-mobile interaction. I could see a mobile-phone box increasing thickness as we receive more text messages, or in a meeting changing shape so as to be more discrete instead of  vibration noises.  

Ted Presentation