Shape Changing Interfaces


Pneumatic interfaces using soft materials have been recently (2013) a new trend in Interface Design and HCI [2]. For us this was a good enough reason to explore possibilities of the material characteristics and interface construction for information representation/ manipulation (c.f. [3]). The video above shows our test software used to drive the interface prototype.

The TUI Hardware Exploration

Following Hiroshi Ishii's vision of tangible representations of information, concepts in which information representation and information manipulation are tightly coupled were developed. In our concept the information was haptically communicated to the human body by in- and deflating the interface. In the opposite direction (human to computer communication) our concept considered different sensing techniques. The main aim here was to integrate selection (e.g. simple push button) and navigation (e.g left, right, up, down), as both are needed for more complex interaction tasks.

For the thermal sensing tests with different types of silicon were conducted, but turned out not very applicable. The image above shows the evaluation of different thicknesses of silicon samples.

Similar to the thermal sensing experiments a series of experiments was conducted to effect the magnetic/ reflective properties of the silicone to detect surface deformation to be used for naviation. Finally we found the optical method to be the most economic.

The Test System

The pictures below show the test system.

The soft actuated button can in- and deflate, detect button press, and 2D navigate.

The control software was written in OpenFramworks.

User Evaluation

While developing the system and playing around with the different technical possibilities and properties, we found skin stretch created by in- and deflating the sphere may create unique user experience and different understandings of tangible information representation. To explore this area more we compared one with and one without the properties of skin stretch.

Users were asked to play a game shown in the figure below and then rate their user experience using the AttrakDiff questionaire. The aim of the game was to collect blue Air Bubbles to get bigger and fly higher. In order to do so one had to avoid the red spears appearing from the left. Once you were hit the interface deflated again and one has to start over.

The results of the questionaire is shown below. Obviously the number of participants (n=5) is much too low for extrapolating from this, but it may give you an indication on what to expect from materials with stretch (Button A) effect compared to those without (Button B).

Our future research will readjust back to the core question and will focus on investigating how skin stretch impacts tangible information representation.




[1] Hiroshi Ishii und Brygg Ullmer: Tangible Bits: Towards Seamless Interfaces between People, Bits and Atoms. Veröffentlicht in Proceedings of Human Factors in Computing Systems: CHI 97, Denver (Colorado).

[2] Lining Yao , Ryuma Niiyama , Jifei Ou , Sean Follmer , Clark Della Silva , Hiroshi Ishii, PneUI: pneumatically actuated soft composite materials for shape changing interfaces, Proceedings of the 26th annual ACM symposium on User interface software and technology, October 08-11, 2013, St. Andrews, Scotland, United Kingdom.

[3] Kristian Gohlke, Eva Hornecker, and Wolfgang Sattler. 2016. Pneumatibles: Exploring Soft Robotic Actuators for the Design of User Interfaces with Pneumotactile Feedback. In Proceedings of the TEI '16: Tenth International Conference on Tangible, Embedded, and Embodied Interaction (TEI '16). ACM, New York, NY, USA, 308-315.



Thomas Kessler (Engineer)
Kristian Gohlke (Advisor)
Patrick Tobias Fischer (Advisor)