3D printing is widely used to physically prototype the look and feel of 3D objects. Interaction possibilities of these prototypes, however, are often limited to mechanical parts or post-assembled electronics. In this paper, we present Capricate, a fabrication pipeline that enables users to easily design and 3D print highly customized objects that feature embedded capacitive multi-touch sensing. The object is printed in a single pass using a commodity multi-material 3D printer. To enable touch input on a wide variety of 3D printable surfaces, we contribute two techniques for designing and printing embedded sensors of custom shape. The fabrication pipeline is technically validated by a series of experiments and practically validated by a set of example applications. They demonstrate the wide applicability of Capricate for interactive objects.

Thermal cameras have recently drawn the attention of HCI researchers as a new sensory system enabling novel interactive systems. They are robust to illumination changes and make it easy to separate human bodies from the image background. Far-infrared radiation, however, has another characteristic that distinguishes thermal cameras from their RGB or depth counterparts, namely thermal reflection. Common surfaces reflect thermal radiation differently than visual light and can be perfect thermal mirrors. In this paper, we show that through thermal reflection, thermal cameras can sense the space beyond their direct field-of-view. A thermal camera can sense areas besides and even behind its field-of-view through thermal reflection. We investigate how thermal reflection can increase the interaction space of projected surfaces using camera-projection systems. We moreover discuss the reflection characteristics of common surfaces in our vicinity in both the visual and thermal radiation bands. Using a proof-of-concept prototype, we demonstrate the increased interaction space for hand-held camera-projection system. Furthermore, we depict a number of promising application examples that can benefit from the thermal reflection characteristics of surfaces.

User input on television (TV) typically requires a mediator device such as a handheld remote control. While this is a well-established interaction paradigm, a handheld device has serious drawbacks: it can be easily misplaced due to its mobility and in case of a touch screen interface, it also requires additional visual attention. Emerging interaction paradigms such as 3D mid-air gestures using novel depth sensors (e.g. Microsoft Kinect), aim at overcoming these limitations, but are known to be tiring. In this article, we propose to leverage the palm as an interactive surface for TV remote control. We present three user studies which set the base for our four contributions: We (1) qualitatively explore the conceptual design space of the proposed imaginary palm-based remote control in an explorative study, (2) quantitatively investigate the effectiveness and accuracy of such an interface in a controlled experiment, (3) identified user acceptance in a controlled laboratory evaluation comparing PalmRC concept with two most typical existing input modalities, here conventional remote control and touch-based remote control interfaces on smart phones for their user experience, task load, as well as overall preference, and (4) contribute PalmRC, an eyes-free, palm-surface-based TV remote control. Our results show that the palm has the potential to be leveraged for device-less eyes-free TV remote interaction without any third-party mediator device.

In this paper, we present a novel device concept that features double-sided displays which can be folded using predefined hinges. The device concept enables users to dynamically alter both size and shape of the display and also to access the backside using fold gestures. We explore the design of such devices by investigating different types and forms of folding. Furthermore, we propose a set of interaction principles and techniques. Following a user-centered design process, we evaluate our device concept in two sessions with low-fidelity and high-fidelity prototypes.

We present a device concept and a prototype of a future mobile device. By featuring a rollable display, its display size and its form factor can be dynamically changed. Moreover, we investigate how physical resizing of the display can be used as an input technique for interacting with digital contents and present a set of novel interaction techniques. Evaluation results show that physical resizing of the display can improve the way we interact with digital contents on mobile devices.