Recent advances in the rapidly growing field of soft robotics highlight the potential for innovations in wearable soft robotics to meet challenges and opportunities affecting individuals, society, and the economy. Some of the most promising application areas include wearable haptic interfaces, assistive robotics, and biomedical devices. Several attributes of soft robotic systems make them well-suited for use in human-wearable applications. Such systems can be designed to accommodate the complex morphology and movements of the human body, can afford sufficient compliance to ensure safe operation in intimate proximity with humans, and can provide context-appropriate haptic feedback or assistance to their wearers. Many soft robotic systems have been designed to resemble garments or wearables that are already widely used today. Such systems could one day become seamlessly integrated into a myriad of human activities and environments. Here, we review emerging advances in wearable soft robotic technologies and systems, including numerous examples from prior research. We discuss important considerations for the design of such systems based on functional concerns, wearability, and ergonomics. We describe an array of design strategies that have been adopted in prior research. We review wearable soft robotics applications in diverse domains, survey sensing and actuation technologies, materials, and fabrication methods. We conclude by discussing frontiers, challenges, and future prospects for soft, wearable robotics.

A key challenge in robotics is to create efficient methods for grasping objects with diverse shapes, sizes, poses, and properties. Grasping with hand-like end effectors often requires careful selection of hand orientation and finger placement. Here, we present a fingerless soft gripper capable of efficiently generating multiple grasping modes. It is based on a soft, cylindrical accordion structure containing coupled, parallel fluidic channels, which are controlled via pressure supplied from a single fluidic port. Inflation opens the gripper orifice for enveloping an object, while deflation allows it to produce grasping forces. The interior is patterned with a gecko-like skin that increases friction, enabling the gripper to lift objects weighing up to 20 N. Our design ensures that fragile objects, such as eggs, can be safely handled, by virtue of a wall buckling mechanism. In reverse, the gripper can be deflated to reach into an opening or orifice then inflated to grasp objects with handles or cavities. The gripper may also integrate a lip that enables it to form a seal and, upon inflating, to generate suction for lifting objects with flat surfaces. In this article, we describe the design and fabrication of this device and present an analytical model of its behavior when operated from a single fluidic port. In experiments, we demonstrate its ability to grasp diverse objects, and show that its performance is well described by our model. Our findings show how a fingerless soft gripper can efficiently perform a variety of grasping operations. Such devices could improve the ability of robotic systems to meet applications in areas of great economic and societal importance.

Integration of soft haptic devices into garments can improve their usability and wearability for daily computing interactions. In this paper, we introduce PneuSleeve, a fabric-based, compact, and highly expressive forearm sleeve which can render a broad range of haptic stimuli including compression, skin stretch, and vibration. The haptic stimuli are generated by controlling pneumatic pressure inside embroidered stretchable tubes. The actuation configuration includes two compression actuators on the proximal and distal forearm, and four uniformly distributed linear actuators around and tangent to the forearm. Further, to ensure a suitable grip force, two soft mutual capacitance sensors are fabricated and integrated into the compression actuators, and a closed-loop force controller is implemented. We physically characterize the static and dynamic behavior of the actuators, as well as the performance of closed-loop control. We quantitatively evaluate the psychophysical characteristics of the six actuators in a set of user studies. Finally, we show the expressiveness of PneuSleeve by evaluating combined haptic stimuli using subjective assessments.

Robots are often envisaged as embodied agents that might be able to intelligently and expressively communicate with humans. This could be due to their physical embodiment, their animated nature, or to other factors, such as cultural associations. In this study, we investigated emotional responses of humans to affective non-linguistic utterances produced by an embodied agent, with special attention to the way that these responses depended on the nature of the embodiment and the extent to which the robot actively moved in proximity to the human. To this end, we developed a new singing robot platform, ROVER, that could interact with humans in its surroundings. We used affective sound design methods to endow ROVER with the ability to communicate through song, via musical, non-linguistic utterances that could, as we demonstrate, evoke emotional responses in humans. We indeed found that the embodiment of the computational agent had an affect on emotional responses. However, contrary to our expectations, we found singing computers to be more emotionally arousing than singing robots. Whether the robot moved or not did not affect arousal. The results may have implications for the design of affective non-speech audio displays for human-computer or human-robot interaction.

This paper proposes a fast, physically accurate method for synthesizing multimodal, acoustic and haptic, signatures of distributed fracture in quasi-brittle heterogeneous materials, such as wood, granular media, or other fiber composites. Fracture processes in these materials are challenging to simulate with existing methods, due to the prevalence of large numbers of disordered, quasi-random spatial degrees of freedom, representing the complex physical state of a sample over the geometric volume of interest. Here, I develop an algorithm for simulating such processes, building on a class of statistical lattice models of fracture that have been widely investigated in the physics literature. This algorithm is enabled through a recently published mathematical construction based on the inverse transform method of random number sampling. It yields a purely time domain stochastic jump process representing stress fluctuations in the medium. The latter can be readily extended by a mean field approximation that captures the averaged constitutive (stress-strain) behavior of the material. Numerical simulations and interactive examples demonstrate the ability of these algorithms to generate physically plausible acoustic and haptic signatures of fracture in complex, natural materials interactively at audio sampling rates.

We investigated the perception of differences between direction-dependent, movement-opposing forces. The magnitude of these forces changed in whenever the direction of motion reversed. They were felt by participants during an experiment that required them to scan a virtual surface, represented by a planar haptic interface, via left-right motions of the index finger. We found that individuals are surprisingly insensitive to changes in opposing force magnitude that are contingent on reversals in direction of motion, despite large contrasts in force magnitude. Forces of 1 N failed consistently to be discriminated from forces of 0 N during sequential presentation at the highest speeds. As the mean scanning speed of the digit was reduced, the effect progressively vanished. The effect we observed is simple and robust enough to be demonstrated on virtually any haptic force-feedback interface. We suggest possible interpretations based on temporal information processing in the nervous system, on physiology and biomechanics, and through inferences that the nervous system may rely on to relate motor commands to sensory input during dynamic haptic interaction. The results obtained raise fundamental questions about the perceptual interpretation of kinesthetic stimuli involving rapid movement, and may also suggest a reconsideration of requirements for haptic interfaces.

This paper reports on emotions felt by users manipulating a computationally and acoustically augmented artifact. Prior studies have highlighted systematic relationships between acoustic features and emotions felt when individuals are passively listening to sounds. However, during interaction with real or computationally augmented artifacts, acoustic feedback results from users' active manipulation of the artifact. In such a setting, both sound and manipulation can contribute to the emotions that are elicited. We report on a set of experimental studies that examined the respective roles of sound and manipulation in eliciting emotions from users. The results show that, while the difficulty of the manipulation task predominated, the acoustical qualities of the sounds also influenced the feelings reported by participants. When the sounds were embedded in an interface, their pleasantness primarily influenced the valence of the users' feelings. However, the results also suggested that pleasant sounds made the task slightly easier, and left the users feeling more in control. The results of these studies provide guidelines for the measurement and design of affective aspects of sound in computationally augmented artifacts and interfaces.

We present techniques to enable users to interact on foot with simulated natural ground surfaces, such as soil or ice, in immersive virtual environments. Position and force estimates from in-floor force sensors are used to synthesize plausible auditory and vibrotactile feedback in response. Relevant rendering techniques are discussed in the context of walking on a virtual frozen pond.

To apply enactive principles within human–computer interaction poses interesting challenges to the way that we design and evaluate interfaces, particularly those that possess a strong sensorimotor character. This article surveys the field of tactile sensory substitution, an area of science and engineering that lies at the intersection of such research domains as neuroscience, haptics, and sensory prosthetics. It is argued that this area of research is of high relevance to the design and understanding of enactive interfaces that make use of touch, and is also a fertile arena for revealing fundamental issues at stake in the design and implementation of enactive interfaces, ranging from engineering, to human sensory physiology, and the function and plasticity of perception. A survey of these questions is provided, alongside a range of current and historical examples.

The computational understanding of continuous human movement plays a significant role in diverse emergent applications in areas ranging from human computer interaction to physical and neuro-rehabilitation. Non-visual feedback can aid the continuous motion control tasks that such applications frequently entail. An architecture is introduced for enabling interaction with a system that furnishes a number of gestural affordances with assistive feedback. The approach combines machine learning techniques for understanding a user's gestures with a method for the display of salient features of the underlying inference process in real time. Methods used include a particle filter to track multiple hypotheses about a user's input as the latter is unfolding, together with models of the nonlinear dynamics intrinsic to the movements of interest. Non-visual feedback in this system is based on a presentation of error features derived from an estimate of the sampled time varying probability that the user's gesture corresponds to the various tracked state trajectories in the different dynamical systems. We describe applications to interactive systems for human gait analysis and rehabilitation, a domain of considerable current interest in the movement sciences and health care.

An interactive system collects noise from a public place and transforms it into content for a public orchestration: the noise is split in specific sounds which are recomposed through sonic interface in a new soundscape. The SoundCam is the most visible part of the Recycling Soundscapes system. It rotates scanning a public space and gives the possibility to spy and to record audio details and voices in the space, even at the big distance. Paradoxically the people in the context involuntary become the center of auditory attention, while the importance of spy fades as the voices start coming out from Sonic Bowls. The Sonic Bowls are instruments that invite passers-by to play with sounds coming from their environment: birds, footsteps, voices. These are collaboratively composed into a new soundscape through SonicBowl interface. The voices are played back randomly as surprise voice messages and build the sound memory of the place. http://www.interaction-ivrea.it/theses/2003-04/architectureofsubtraction/ReSound.htm