Steven Nagels*, Raf Ramakers*, Kris Luyten, Wim Deferme
In Proceedings of CHI'18

We present a scalable Do-It-Yourself (DIY) fabrication workflow for prototyping highly stretchable yet robust devices using a CO2 laser cutter, which we call Silicone Devices. Silicone Devices are self-contained and thus embed components for input, output, processing, and power. Our approach scales to arbitrary complex devices as it supports techniques to make multi-layered stretchable circuits and buried VIAs. Additionally, high-frequency signals are supported as our circuits consist of liquid metal and are therefore highly conductive and durable. To enable makers and interaction designers to prototype a wide variety of Silicone Devices, we also [..]

Danny Leen*, Raf Ramakers*, Kris Luyten
In Proceedings of UIST '17

We present StrutModeling, a computationally enhanced construction kit that enables users without a 3D modeling background to prototype 3D models by assembling struts and hub primitives in physical space. Physical 3D models are immediately captured in software and result in readily available models for 3D printing. Given the concrete physical format of strutmodels, modeled objects can be tested and fine tuned in the presence of existing objects and specific needs of users. StrutModeling avoids puzzling with pieces by contributing an adjustable [..]

Raf Ramakers, Fraser Anderson, Tovi Grossman, George Fitzmaurice
In Proceedings of CHI '16 (Best Paper Honorable Mention Award)

RetroFab is an end-to-end design and fabrication environment that allows non-experts to retrofit physical interfaces. Our approach allows for changing the layout and behavior of physical interfaces. Unlike customizing software interfaces, physical interfaces are often challenging to adapt because of their rigidity. With RetroFab, a new physical interface is designed that serves as a proxy interface for the legacy controls that are now operated by actuators. RetroFab makes this concept of retrofitting devices available to non-experts by automatically generating an enclosure structure from an annotated 3D scan. This enclosure structure holds [..]

Raf Ramakers, Kashyap Todi, Kris Luyten
In Proceedings of CHI '15, Demo at CHI '15, Demo + Talk + Poster at SIGGRAPH '15

PaperPulse is a design and fabrication approach that enables designers without a technical background to produce standalone interactive paper artifacts by augmenting them with electronics. With PaperPulse, designers overlay pre-designed visual elements with electronic components available in our design tool. PaperPulse provides designers with three families of widgets designed for smooth integration with paper, for an overall of 20 different interactive components. We also contribute a [..]

Raf Ramakers, Johannes Schöning, Kris Luyten
In Proceedings of CHI '14. ( + videoshowcase)

We present the concept of highly deformable mobile devices that can be transformed into various special-purpose controls in order to bring physical controls to mobile devices. Physical controls have the advantage of exploiting people's innate abilities for manipulating physical objects in the real world. We designed and implemented a prototype, called Paddle, to demonstrate our concept. Additionally, we explore the interaction techniques enabled by this concept and [..]

Kickables: Tangibles for Feet

Dominik Schmidt, Raf Ramakers, Esben Pedersen, Johannes Jasper, Sven Köhler, Aileen Pohl, Hannes Rantzsch, Andreas Rau, Patrick Schmidt, Christoph Sterz, Yanina Yurchenko, Patrick Baudisch
In Proceedings of CHI '14.

We introduce the concept of tangibles that users can manipulate with their feet. We call them kickables. Unlike traditional tangibles, kickables allow for very large interaction surfaces as kickables reside on the ground. The main benefit of kickables over other foot-based modalities, such as foot touch, is their strong affordance, which we validate in two user studies. This affordance makes kickables well-suited for walk-up installations, such as tradeshows or [..]

Raf Ramakers, Davy Vanacken, Kris Luyten, Karin Coninx and Johannes Schöning
In Proceedings of UIST '12.

Interactive surfaces have great potential for co-located collaboration because of their ability to track multiple inputs simultaneously. However, the multi-user experience on these devices could be enriched significantly if touch points could be associated with a particular user. Existing approaches to user identification are intrusive, require users to stay in a fixed position, or suffer from poor accuracy. We present a [..]

Workshop Papers

Mixed-Initiative Visual Programming Paradigms for Authoring Sensor-Based Systems

Raf Ramakers, Kris Luyten
Workshop on Mixed-Initiative Creative Interfaces, CHI '17.

Most users of computing devices are non-programmers and are limited to passive consumers of the technology that is made available to them. While research on end-user design environments resulted in procedures to automatically generate design and electronic aspects of sensor-based systems, automated code generation is limited to simple repetitive tasks. In this position paper, we explore mixed-initiative approaches to assist users in specifying logic for sensor-based systems. By combining visual programming and machine learning concepts, our approach presents a [..]

An End-User Development Approach for Designing and Fabricating Interactive Paper

Raf Ramakers, Kashyap Todi, Kris Luyten
Workshop on End User Development in the Internet of Things Era, CHI '15.

This paper covers PaperPulse, a design and fabrication approach that enables designers to produce standalone interactive paper artifacts by augmenting them with electronics. With PaperPulse, users overlay visual designs with widgets provided in the design tool. PaperPulse provides different families of widgets, designed for smooth integration with paper, for a total of 20 different interactive components. We also contribute a demonstration and recording approach, Pulsation, that allows specifying interaction[..]

Learning from 3D puzzles to inform future interactions with deformable mobile interfaces

Raf Ramakers, Kris Luyten, Johannes Schöning
Workshop on Displays Take New Shape: An Agenda for Interactive Surfaces, CHI '13.

Nowadays, an increasing number of people use ensembles of differently sized mobile devices to accomplish different tasks. With advances in display and input technologies, such as flexible and deformable OLED and E-ink displays, we can close the gap between different form factors and offer devices that can be deformed and transformed for different purposes. In this paper, we explore [..]


End-User Control over Physical User-Interfaces: From Digital Fabrication to Real-Time Adaptability

PhD Dissertation, December 2016

Enriching Touch

Master Thesis, January 2012

In this thesis, I explored different dimensions to enhance traditional 2D touch input on screens i.e. touch screens with information, such as the identity of the user, pressure sensitivity and the orientation of fingers or users towards the screen. I developed a novel touch identification technique to associate touches to hands and users that we later published in a UIST paper.

Magic Lenses for Visualising Multimedia Data

Bachelor Thesis, June 2010

Semi-transparent overlays, called "magic lenses" are used in this thesis to explore vast video archives. These magic lenses were used to find both videos as well as specific fragments in these videos. New interaction techniques were investigated to create relations between these lenses in order to build arbitrary complex queries. During a summer job in 2010, I extended the software to support more extensive filtering mechanisms, collaborative search and more media archives including YouTube. The software was later used during various exhibitions at the University.

Image 1 | Image 2 | Image 3