Prof. Dr. Patrick Baudisch

The Human Computer Interaction Lab

We believe that computer science and mechanical engineering are about to unite. In the future, users will solve mechanical problems by digitizing the involved objects using 3D scanners, solving the problem in the digital domain using the means of computer science, and converting the result back to the mechanical domain using a 3D printer. This will allow solving mechanical problems with the effectiveness and efficiency of computer science, including the ability to scale massively.

This will not only change mechanical engineering, but also allow computing to reach its next phase, which is to merge into matter itself, where the physical matter of objects will also perform the computation, rather than separate micro controllers.

The role of our group is to drive this unification process, in particular by creating and re-purposing fabrication machines and haptic machinery.

Patrick Baudisch and Stefanie Mueller. Personal Fabrication. 
In Foundations and Trends. 2017. 133 pages PDF.

Keynote on personal fabrication given at Interactions in Tokyo, Korean HCI, and AVI in Bari


Kerfmeter(full paper at CHI 23) is a hardware + software device that automati- cally determines how much material the laser cutter burns of, also known as kerf. Its knowledge about kerf allows Kerfmeter to make the joints of laser cut 3D models ft together with just the right tension.

HingeCore (full paper at UIST 22) is a novel type of laser-cut structure, the key element of which is what we call finger hinges  which we produce by laser-cutting foamcore “half-way”. Our HingeCoreMaker software automatically converts 3D models into such 2D cutting plans. The resulting models are particularly easy and fast to assemble, while also being sturdy.

FoolProofJoint (full paper at CHI 22) is a software tool that simplifies the assembly of laser-cut 3D models and reduces the risk of erroneous assembly. FoolProofJoint achieves this by modifying finger joint patterns.

autoAssembler (full paper at UIST 2021) is a software tool that automatically converts 2D cutting plans for laser cutting to 3D models, by beam searching the exponential space of possible ways to combine plates in the cutting plan using a heuristic function that scores "good assemblies"

Roadkill (full paper at UIST 2021) is a software tool that converts 3D models to 2D cutting plans for laser cutting—such that the resulting layout allows for fast assembly. Roadkill achieves this with the help of a visual language that conveys assembly instructions directly in the generated layout and by collocating plates to be joined, thereby minimizing visual search.

Assembler3 (full paper at CHI 2021) is a software tool that allows users to make 3D parametric modifications to 2D cutting plans for laser cutting, by semi-automatically reconstructing the 3D model. The resulting models are truly portable in that they fabricate on any machine and can be modified to user's individual needs. 

fastForce (full paper at CHI 2021) is a software tool that detects structural flaws in laser-cut 3D models and fixes them by introducing additional plates into the model, thereby making models up to 52x stronger.

Kerf-Canceling Mechanisms (full paper at UIST 2020) presents a kerf-canceling mechanisms for laser-cutting that work on any laser cutter/milling machine. Together with SpringFit, it enables users to turn SVGs for laser cutting into a machine-independent format.

SpringFit (full paper at UIST 2019) presents a solution to make mounts and joints for laser-cutting work on any laser cutter. As opposed to the typical machine-specific SVG model that works great on one machine but may fail on any other cutter. 

kyub (full paper at CHI 2019) is a 3D modeling environment for laser cutting, first introduced in this paper. The core idea: a WYSIWYG modeling environment that allows users to quicky build sturdy structures by modeling with volumetric elements (boxels). 

LaserStacker (full paper at UIST 2015) LaserStacker allows users to fabricate 3D objects with an ordinary laser cutter through a cut-weld-heal-release process. The key idea is to use the laser cutter to not only cut but also to weld. 

Platener (best paper nominee at CHI 2015) speeds up design iterations of 3D models by extracting straight and curved plates from the 3D model and substituting them with laser cut parts. 

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

Human-scale personal fabrication

AirTied (full paper at UIST 2023): AirTied is a device that automated the fabrication of large-scale structures. The resulting truss structures can be produced with a device much smaller than the structure itself, making the technology viable for novices.

Trusscillator (full paper at UIST'21) is an end-to-end system that allows non-engineers to create human-scale human-powered devices that perform oscillatory movements, such as playground equipment, workout devices, and interactive kinetic installations.

TrussFormer (full paper at UIST'18) end-to-end system that allows users to 3D print large-scale kinetic structures, i.e., structures that involve motion and deal with dynamic forces.

TrussFab (full paper at CHI 2017) an integrated end-to-end system that allows users to fabri-cate large scale structures that are sturdy enough to carry human weight. TrussFab achieves the large scale by complementing 3D print with plastic bottles.

Protopiper (full paper at UIST 2015) Physically Sketching Room-Sized Objects at Actual Scale. The key idea behind protopiper is that it forms adhesive tape into tubes as its main building material, rather than extruded plastic or photopolymer lines.

Virtual Reality

Scenograph(fullpaper at UIST 2018) allows real-walking VR experiences to run in arbitrary tracking volumes.

VirtualSpace(fullpaper at CHI 2018) allows multiple users in virtual reality to use the same tracking space at the same time. The users are immersed in different virtual worlds and not aware of one another.

Haptic interfaces for visually impaired users

DualPanto (fullpaper at UIST'18) is a new haptic device that enables blind users to continuously track the absolute position of moving objects in spatial virtual environments, as is the case in sports or shooter games.

Linespace (fullpaper at CHI'16) is an interactive system that consists of hardware and software and that allows visually impaired users to interact with spatial contents.


Understanding Metamaterial Mechanisms (CHI '19) investigates the underlying topological constraints of shearing and rigid cells and their influence on the resulting mechanism. Based on these findings, we contribute a computational design tool that automatically creates a metamaterial mechanism from user-defined motion paths.

Metamaterial Textures (CHI '18) investigates 3D printed surface geometries that based on their interal cell structure can perform a controlled transition between two or more textures. 

Digital Mechanical Metamaterials(CHI '17) proposes integrating computational abilities into the structure of 3D printed objects. While analog metamaterial mechanisms are subject to damping, causing the mechanical "signal" to decay, digital mechanical metamaterials allow an arbitrary number of cells. 

Metamaterial Mechanisms (best paper nominee at UIST'16) integrate mechanical functionality within the material structure. Such Mechanisms consist of a single block of 3D printed material with cells that play together to redirect forces, thereby implementing mechanisms.

Haptics using electrical muscle stimulation

We investigate how users might interact with devices smaller than mobile or wearable devices. We argue that to achieve the intended minimal form-factor such devices will leverage the user's body as an input and output device. We explore controlling the user's limbs using electrical muscle stimulation. Find out more.

Feel what you touch in AR (fullpaper at CHI 2018) utilizes electrical muscle stimulation to providing haptics to Mixed and Augmented Reality (AR & MR) without ever covering the users hands. This allows users to still be able to seemlessly interact with their real suroundings.

VR walls (fullpaper at CHI 2017) utilizes electrical muscle stimulation to providing haptics to walls and other heavy objects in virtual reality. The resulting system is wearable and fits in a backpack.

Ad Infinitum (exhibition at ARS Electronica 2017, Science Gallery Dublin 2017) is a parasitical entity that uses electrical muscle stimulation to lives off human energy. This parasite reverses the dominant role that mankind has with respect to technologies: the parasite shifts humans from "users" to "used".

Muscle-plotter is an interactive system based on EMS that produces spatial output. It achieves this by persisting EMS output by actuating the user's wrist as to plot with an Anoto pen. Muscle-plotter is the first EMS-based sensemaking system. 

Impacto (full paper at UIST 2015) is a wearable device that simulates the sensation of physical impact in virtual reality. It does so by decomposing the stimuli into (1) the tactile sensation, which is rendered by tapping the user's skin with a solenoid, and (2) the impulse, which is rendered by actuating the user's body with electrical muscle stimulation. 

Affordance++ (best paper, fullpaper at CHI 2015) allows everyday objects to communicate dynamic use: motion (spray can shakes when touched), multi-step processes (peeling an avocado), and behaviors that change over time (don't grab the hot cup by its body). 

Proprioceptive Interaction (fullpaper at CHI 2015) allows for eyes-free interaction based on proprioception alone. We devised a bracelet which allows to input and output to happen exclusively through the user's muscles.

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).

Haptics using human actuation

iTurk (fullpaper at CHI 2018) makes the user reconfigure otherwise passive haptics to convey a sense of a living, animate virtual world with haptic feedback, while in reality the user is the only animate entity present in the system. 

Mutual Human Actuation (full paper at UIST 2017) leverages human actuation but eliminates the need of dedicated human actuators by making them as players. The players are fully immersed into their own virtual experiences while providing the other haptic feedback.

TurkDeck(full paper at UIST 2015) is a prop based VR system which leverages human actuation to move and re-organise the props in the scene. In combination with portals to move between rooms this results in scalable  prop based VR. 

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.

Level-Ups(note at CHI 2015) are computer-controlled stilts that allow virtual reality users to experience walking up and down steps. Unlike traditional solutions that are integrated with locomotion devices, Level-Ups allow users to walk around freely.

3D Printing

FormFab: Towards Shape Exploration in Interactive Fabrication (full paper at TEI 2019) FormFab is a fabrication system that reshapes the workpiece while users are moving their hands. This enables users to interactively explore different sizes of a shape with a single interaction.

Grafter (full paper at CHI 2018) allows users to remix 3D printed machines. It leverages the mechanical knowledge stored in 3D printed files that are shared on the web and provides an editor that allows easy recombination of these into new and more advanced machines

RoMA: Interactive Fabrication with a Robotic Arm 3D Printer
Huaishu Peng, Cheng-Yao Wang, James Briggs, Kevin Guo, Joseph Kider, Stefanie Mueller, Patrick Baudisch and Francois Grumbetière
In Proceedings of CHI'18. 

Mobile Fabrication (full paper at UIST 2016) we studied mobile 3D-printing in order to find out what people would make on the go and how technology can enable true mobile fabrication

Destructive Games (note at CHI 2016) are games that result in valuable physical objects being damaged or destroyed. Surprisingly, 8 out of 12 participants would play again.

Patching Physical Objects (full paper at UIST 2015) Instead of re-printing the entire object from scratch during design iteration, we suggest patching the existing object and replacing only the unsatisfactory parts.


Scotty (full paper at TEI 2015) is a simple self-contained appliance that allows relocating inanimate physical objects across distance.

WirePrint  (full paper at UIST 2014) 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.

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

gravity + multitouch = 3D tracking (since 2010)

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

Ergonomic Interaction on Touch Floors (fullpaper at CHI 2015). The main appeal of touch floors is that they are the only direct touch form factor that scales to arbitrary size. In this paper, we argue that the price for this benefit is bad physical ergonomics, and propose addressing this issue by allowing users to operate touch floors in any pose they like.

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)

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

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.