The objective of our work is to unify the virtual world of the computer with the physical world of the user into a single "Euclidean" space. We argue that this is the key to intuitive or “natural” user interfaces. For details, see our two keynotes:

2012-2013 Keynote: Natural User Interface Hardware

"What makes an interface natural" and "why can 1-year olds use touch screens"? I discuss NUI at the example of prototype devices that unify the virtual world of the computer with the physical world of the user into a single "Euclidean" space. 
PPT 54.6MB
 given at British HCI 2012 and 3DUI 2013

2010-2011 Keynote: My new PC is a mobile phone

I argue that the computational device for the world is already here--it is mobile phones. 4 billion of them. But to make them useful, we need to create new software that turns phones into stand-alone computers.
PPT+Video 116.3M given at Mobile HCI 2010 and USAB 2010

Mobile force-feedback (since 2013)

Haptic Turk (fullpaper at CHI 2014) offers the functionality of a motion platform--but is based on people. Allows bringing motion the concept of immersive haptic experiences to millions of users.

Muscle-Propelled Force-Feedback (note at CHI 2013) provides force feedback via electrical muscle stimulation, e.g., in interactive games. This saves the exoskeleton and motors, making the approach mobile.

Gesture Output (fullpaper at CHI 2013) allows mobile touch devices to send eyes-free messages to the user as a sequence of marks of graffiti characters via our force-feedback touch screen (PocketOuija).

Interactive construction (since 2012)

FaBrickation (fullpaper at CHI 2014) speeds up fabrication time of functional 3D printed objects by integrating construction kit building blocks.

LaserOrigami (best paper award at CHI 2013) allows users to produce fully assembled 3D objects using a laser-cutter--two orders of magnitude faster than with a 3D printer.

Constructable (fullpaper at UIST 2012) allows users to create physical objects by drawing directly on the workpiece while in the laser cutter

WirePrint prints 3D objects as wireframe previews. By extruding filament directly into 3D space instead of printing layer-wise, it achieves a speed-up of up to a factor of 10, allowing designers to iterate more quickly in the early stages of design.

gravity + multitouch = 3D tracking (since 2010)

Kickables (fullpaper at CHI 2014) are tangibles for feet, which provide tangible experiences for large scale installations with interactive floors.

Fiberio (fullpaper UIST 2013) is a multitouch table that senses fingerprints and identifies users biometrically during each touch.

GravitySpace (best paper nominee at CHI 2013) tracks users and their poses in smart rooms based on the latest 8m2 version of our pressure-sensing multitoe floor.

Bootstrapper (note at CHI 2012) recognizes tabletop users by their shoes. Bootstrapper uses a Kinect attached to a Microsoft Surface table pointed at users' shoes.

CapStones and ZebraWidgets (note CHI 2012) are stackable building blocks, dials and widgets for capacitive touch screens that work by handing down capacitance.

Multitoe (fullpaper UIST 2010) is an interactive floor. Based on FTIR sensing, it can identify users based on their soles, track users' foot and body postures, and enable high-precision interaction-using feet.

Lumino (best paper award CHI 2010, demos at Siggraph 2010 and Tabletop 2010) is a system of building blocks that allows microsoft surface to sense building elements arranged in three-dimensional structures.

RidgePad was our first project to explore 3D reconstruction from contact area.

Imaginary interfaces = spatial gestures (since 2010)

Imaginary Reality Games (paper UIST 2013) are games that mimic real-world sport, such as basketball or soccer, except that there is no visible ball.

Understanding palm-based imaginary interfaces (fullpaper CHI 2013) allow users to interact with unfamiliar imaginary interfaces. We also explore revisit the fundamentals of imaginary interfaces, i.e. the role of visual and tactile cues.

BodyScape (best paper nominee CHI 2013) a body-centric design space for exploring how users may interact across the surfaces of their body.

Imaginary Phone (fullpaper UIST 2011) allows users to operate their phone without taking it out of the pocket. Instead users type on their hand. Users learn the device automatically by transferring spatial knowledge from the use of the physical device.

Data Miming (fullpaper CHI 2011). Users retrieve 3D objects from a database by describing their shape through gesture in 3-space. Tracked using a Kinect/PrimeSense depth camera.

Imaginary Interfaces (fullpaper UIST 2010) are devices that allow users to interact spatially as they normally would with a touch screen--yet without the screen.

Understanding touch (since 2010)

Understanding touch (fullpaper at CHI 2011). In order for a touch device to be highly effective it needs to match users' mental model of touch. But what is that model?

Touch on Curved Surfaces (fullpaper CHI 2011). Technology is emerging that allow touch-enabling non-planar surfaces, e.g., on mobile devices. We are modeling how users interact with such surfaces.

Generalized perceived input point model & ridgepad (fullpaper at CHI 2010). We find that the touch location sensed by capacitive touchpads varies across users and finger postures. We build a device based on a fingerprint scanner that exploits this.

Miniature mobile devices (since 2009)

Implanted User Interfaces (full paper CHI 2012) establish that input controls, output components, and components for wireless communication and charging work through human skin.

Rock-Paper-Fibers: (note CHI 2012) Bringing Physical Affordance to Mobile Touch Devices.

Deformable touch devices based on time domain reflectometry (best paper nominee UIST 2011) allow touch-enabling stretchable, reconfigurable, and modular devices, all with a single two-wire cable.

Nenya (note at CHI 2011). This input device is a passive magnetic ring. We obtain this tiny device form-factor by offloading all electronics into a bracelet that tracks the ring using a magnetometer.

Touch Projector (fullpaper CHI 2010) allows users to manipulate the contents located on distant public displays by touch manipulating its video image on their mobile device.

Disappearing Mobile Devices (fullpaper UIST 2009) are devices so small, that they only allow certain types of gesture interactions: a thought experiment about the ultimate future of mobile miniaturization.

Nanotouch (best paper nominee CHI 2009) is a prototype device that users operate via the device backside. Allows for making very small mobile devices.


Let's kick it (note at CHI 2014) makes the unreachable bottom of vertical displays fully interactive by expanding direct touch to the feet.

360° Panoramic Overviews (note CHI 2012) allow users to get an overview of a augmented reality scene without losing spatial orientation.

Relaxed Selection Techniques (fullpaper UIST 2009) allow users to search time series data using a pen stroke that not only specifies the shape of the sought segment, but also specifies tolerances.