Interaction Support for Hybrid Groups of Paper and Digital Documents on Tabletops

Based on the results of a user study, this paper presents a set of hybrid interaction techniques for groups of paper and digital documents on interactive surfaces. By leveraging a novel concept of tangible controls, these techniques allow highly flexible, fluid and lightweight interactions

Feather Hair : Interacting with Sensorized Hair in Public Settings

Human hair opens up new opportunities for embodied interactions that build on its unique physical affordances and location on the body. As hair has high socio-cultural significance, the design of hair interfaces is coupled with social and personal needs. Albeit this makes field investigations indispensable, they are missing from prior work. We present a fabrication approach for gesture-controlled hair interfaces that are robust enough to be deployed in the field. Our approach contributes sensorized feather hair extensions that combine capacitive and piezoresistive sensing. Their tactile properties make the interface blend seamlessly with human hair. We furthermore contribute results from a field experiment where participants gained first-hand experience in various social contexts. These show how hair-based interactions have great potential moving beyond planar touch gestures whilst their social appropriateness is context-sensitive. We synthesize the findings into design implications that ground the future design of usable and socially acceptable hair interfaces

Soft Inkjet Circuits: Rapid Multi-Material Fabrication of Soft Circuits using a Commodity Inkjet Printer

Despite the increasing popularity of soft interactive devices, their fabrication remains complex and time consuming. We contribute a process for rapid do-it-yourself fabrication of soft circuits using a conventional desktop inkjet printer. It supports inkjet printing of circuits that are stretchable, ultrathin, high resolution, and integrated with a wide variety of materials used for prototyping. We introduce multi-ink functional printing on a desktop printer for realizing multi-material devices, including conductive and isolating inks. We further present DIY techniques to enhance compatibility between inks and substrates and the circuits' elasticity. This enables circuits on a wide set of materials including temporary tattoo paper, textiles, and thermoplastic. Four application cases demonstrate versatile uses for realizing stretchable devices, e-textiles, body-based and re-shapeable interfaces

Computational design and optimization of electro-physiological sensors

Electro-physiological sensing devices are becoming increasingly common in diverse applications. However, designing such sensors in compact form factors and for high-quality signal acquisition is a challenging task even for experts, is typically done using heuristics, and requires extensive training. Our work proposes a computational approach for designing multi-modal electro-physiological sensors. By employing an optimization-based approach alongside an integrated predictive model for multiple modalities, compact sensors can be created which offer an optimal trade-off between high signal quality and small device size. The task is assisted by a graphical tool that allows to easily specify design preferences and to visually analyze the generated designs in real-time, enabling designer-in-the-loop optimization. Experimental results show high quantitative agreement between the prediction of the optimizer and experimentally collected physiological data. They demonstrate that generated designs can achieve an optimal balance between the size of the sensor and its signal acquisition capability, outperforming expert generated solutions

Like a Second Skin: Understanding How Epidermal Devices Affect Human Tactile Perception

The emerging class of epidermal devices opens up new opportunities for skin-based sensing, computing, and interaction. Future design of these devices requires an understanding of how skin-worn devices affect the natural tactile perception. In this study, we approach this research challenge by proposing a novel classification system for epidermal devices based on flexural rigidity and by testing advanced adhesive materials, including tattoo paper and thin films of poly (dimethylsiloxane) (PDMS). We report on the results of three psychophysical experiments that investigated the effect of epidermal devices of different rigidity on passive and active tactile perception. We analyzed human tactile sensitivity thresholds, two-point discrimination thresholds, and roughness discrimination abilities on three different body locations (fingertip, hand, forearm). Generally, a correlation was found between device rigidity and tactile sensitivity thresholds as well as roughness discrimination ability. Surprisingly, thin epidermal devices based on PDMS with a hundred times the rigidity of commonly used tattoo paper resulted in comparable levels of tactile acuity. The material offers the benefit of increased robustness against wear and the option to re-use the device. Based on our findings, we derive design recommendations for epidermal devices that combine tactile perception with device robustness

A cuttable multi-touch sensor

We propose cutting as a novel paradigm for ad-hoc customization of printed electronic components. As a first instantiation, we contribute a printed capacitive multi-touch sensor, which can be cut by the end-user to modify its size and shape. This very direct manipulation allows the end-user to easily make real-world objects and surfaces touch-interactive, to augment physical prototypes and to enhance paper craft. We contribute a set of technical principles for the design of printable circuitry that makes the sensor more robust against cuts, damages and removed areas. This includes novel physical topologies and printed forward error correction. A technical evaluation compares different topologies and shows that the sensor remains functional when cut to a different shape.Deutsche Forschungsgemeinschaft (Cluster of Excellence Multimodal Computing and Interaction, German Federal Excellence Initiative

PrintSense: a versatile sensing technique to support multimodal flexible surface interaction

We present a multimodal on-surface and near-surface sensing technique for planar, curved and flexible surfaces. Our technique leverages temporal multiplexing of signals coming from a universal interdigitated electrode design, which is printed as a single conductive layer on a flexible substrate. It supports sensing of touch and proximity input, and moreover is capable of capturing several levels of pressure and flexing. We leverage recent developments in conductive inkjet printing as a way to prototype electrode patterns, and combine this with our hardware module for supporting the full range of sensing methods. As the technique is low-cost and easy to implement, it is particularly well-suited for prototyping touch- and hover-based user interfaces, including curved and deformable ones

How to visualize a quantum transition of a single atom

The previously proposed visualization of Rabi oscillations of a single atom by a continuous fuzzy measurement of energy is specified for the case of a single transition between levels caused by a $\pi$-pulse of a driving field. An analysis in the framework of the restricted-path-integral approach (which reduces effectively to a Schr\"odinger equation with a complex Hamiltonian) shows that the measurement gives a reliable information about the system evolution, but the probability of the transition becomes less than unity. In addition an experimental setup is proposed for continuous monitoring the state of an atom by observation of electrons scattered by it. It is shown how this setup realizes a continuous fuzzy measurement of the atom energy.Comment: LATEX, 15 pages, 2 figures (EPS), to be published in Phys. Let.

Designing Pen-and-Paper User Interfaces for Interaction with Documents

Despite numerous predictions of the paperless office, knowledge work is still characterized by the combined use of paper and digital documents. Digital pen-and-paper user interfaces bridge the gap between both worlds by electronically capturing the interactions of a user with a pen on real paper. The contribution of this paper is two-fold: First, we introduce an interaction framework for pen-and-paper user interfaces consisting of six core interactions. This helps both in analyzing existing work practices and interfaces and in guiding the design of interfaces which offer complex functionality and nevertheless remain simple to use. Second, we apply this framework and contribute three novel pen-and-paper interaction strategies for creating hyperlinks between printed and digital documents and for tagging both types of documents