Konstantin Käfer

Multitoe: Multitouch with feet

Traditional touch screens suffer from a limitation of size—tabletops for example can’t become larger than arm’s length because you couldn’t reach the objects in the middle. With Multitoe, we propose a touch screen floor that could fill an entire room and allows for many more objects by using high-resultion multi-touch tracking while still allowing direct manipulation by touching.

We used frustrated total internal reflection due to its ability to sense pressure. This allows us to see the users’ soles while they are walking over the floor. Based on this, we can recognize the foot posture and identify users, or control applications with a high degree of freedom.

Presentation at UIST 2010, New York City

About the project

Multitoe is a research project by Thomas Augsten, Konstantin Käfer, Rene Meusel, Caroline Fetzer, Dorian Kanitz, Thomas Stoff, Christian Holz, and Torsten Becker at the Human Computer Interaction Lab of Prof. Patrick Baudisch at Hasso Plattner Institute from fall 2009 to summer 2010. A new group of students continued the research.


Augsten, T., Kaefer, K., Meusel, R., Fetzer, C., Kanitz, D., Stoff, T., Becker, T., Holz, C. and Baudisch, P. Multitoe: High-Precision Interaction with Back-Projected Floors Based on High-Resolution Multi-Touch Input. In Proceedings of UIST 2010, pp. 209-218.

More information


Photos by Kay Herschelmann.