We introduce a novel, fabric-based, flexible, and stretchable tactile sensor, which is capable of seamlessly covering natural shapes. As humans and robots have curved body parts that move with respect to each other, the practical usage of traditional rigid tactile sensor arrays is limited. Rather, a flexible tactile skin is required. Our design allows for several tactile cells to be embedded in a single sensor patch. It can have an arbitrary perimeter and can cover free-form surfaces. In this article we discuss the construction of the sensor and evaluate its performance. Our flexible tactile sensor remains operational on top of soft padding such as a gel cushion, enabling the construction of a human-like soft tactile skin. The sensor allows pressure measurements to be read from a subtle less than 1 kPa up to high pressures of more than 500 kPa, which easily covers the common range for everyday human manual interactions. Due to a layered construction, the sensor is very robust and can withstand normal forces multiple magnitudes higher than what could be achieved by a human without sustaining damage.As an exciting application for the sensor, we describe the construction of a wearable tactile dataglove with 54 tactile cells and embedded data acquisition electronics. We also discuss the necessary implementation details to maintain long term sensor performance in the presence of moisture

The feeling of embodiment, i.e., experiencing the body as belonging to oneself and being able to integrate objects into one's bodily self-representation, is a key aspect of human self-consciousness and has been shown to importantly shape human cognition. An extension of such feelings toward robots has been argued as being crucial for assistive technologies aiming at restoring, extending, or simulating sensorimotor functions. Empirical and theoretical work illustrates the importance of sensory feedback for the feeling of embodiment and also immersion; we focus on the the perceptual level of touch and the role of tactile feedback in various assistive robotic devices. We critically review how different facets of tactile perception in humans, i.e., affective, social, and self-touch, might influence embodiment. This is particularly important as current assistive robotic devices – such as prostheses, orthoses, exoskeletons, and devices for teleoperation–often limit touch low-density and spatially constrained haptic feedback, i.e., the mere touch sensation linked to an action. Here, we analyze, discuss, and propose how and to what degree tactile feedback might increase the embodiment of certain robotic devices, e.g., prostheses, and the feeling of immersion in human-robot interaction, e.g., in teleoperation. Based on recent findings from cognitive psychology on interactive processes between touch and embodiment, we discuss technical solutions for specific applications, which might be used to enhance embodiment, and facilitate the study of how embodiment might alter human-robot interactions. We postulate that high-density and large surface sensing and stimulation are required to foster embodiment of such assistive devices.

In this paper we introduce a novel way of producing highly sensitive 3D-shaped tactile sensors. The sense of touch is critical for enabling humans to master intricate manual interactions. Numerous anthropomorphic robots make extensive use of complex three dimensional body parts in mimicry of their biological counterparts. We use laser structuring technology to augment freeform surfaces with conductive tracks, paving the way for the manufacturing of 3D-shaped tactile sensors. The signal acquisition electronics can be effortlessly embedded on the backside of an artificial layer of skin. We evaluate the performance of the sensor and discuss the results in detail. As an exciting application, we produced a tactile fingertip sensor for the Shadow Robot Hand that incorporates 12 tactile sensor regions and the embedded signal acquisition electronics. The integrated microcontroller is able to capture force patterns with a frame-rate of more than 1 kHz, allowing object slippage to be detected.

Tactile sensing is an important field of research in the domains of human-computer and human-robot interaction. To provide appropriate tactile sensing capabilities, this work presents the development of a new modular tactile sensor system focusing especially on high frame rates (up to 1.9 kHz) and good spatial resolution (5 mm). Larger sensor areas are composed from identical sensor modules providing a 16×16 matrix of tactels. We compare different tactel layouts and different force-sensitive materials to achieve optimal sensitivity especially to low forces in order to facilitate detection of first touch. An example application demonstrates the capability of the developed sensor to detect tiny variations in applied force.

We present our second generation tactile sensor for the Shadow Dexterous Hand’s palm. We were able to significantly improve the tactile sensor characteristics by utilizing our latest barometer-based tactile sensing technology with linear (R ² ≥ 0.9996) sensor output and no noticeable hysteresis. The sensitivity threshold of the tactile cells and the spatial density were both dramatically increased. We demonstrate the benefits of the new sensor by re-running an experiment to estimate the stiffness of different objects that we originally used to test our first generation palm sensor. The results underline a considerable performance boost in estimation accuracy, just due to the improved tactile skin. We also propose a revised neural network architecture that even further improves the average classification accuracy to 96% in a 5-fold cross-validation.