1,572 research outputs found
Potential merits for space robotics from novel concepts of actuation for soft robotics
Autonomous robots in dynamic and unstructured
environments require high performance, energy
efficient and reliable actuators. In this paper we
give an overview of the first results of two lines of
research regarding the novel actuation principle
we introduced: Series-Parallel Elastic Actuation
(SPEA). Firstly, we introduce the SPEA concept
and present first prototypes and results.
Secondly, we discuss the potential of self-healing
materials in robotics, and discuss the results on
the first self-healing pneumatic cell and selfhealing
mechanical fuse. Both concepts have the
potential to improve performance, energy
efficiency and reliability
Bio-inspired Tensegrity Soft Modular Robots
In this paper, we introduce a design principle to develop novel soft modular
robots based on tensegrity structures and inspired by the cytoskeleton of
living cells. We describe a novel strategy to realize tensegrity structures
using planar manufacturing techniques, such as 3D printing. We use this
strategy to develop icosahedron tensegrity structures with programmable
variable stiffness that can deform in a three-dimensional space. We also
describe a tendon-driven contraction mechanism to actively control the
deformation of the tensegrity mod-ules. Finally, we validate the approach in a
modular locomotory worm as a proof of concept.Comment: 12 pages, 7 figures, submitted to Living Machine conference 201
A soft, synergy-based robotic glove for grasping assistance
This paper presents a soft, tendon-driven, robotic glove designed to augment grasp capability and provide rehabilitation assistance for postspinal cord injury patients. The basis of the design is an underactuation approach utilizing postural synergies of the hand to support a large variety of grasps with a single actuator. The glove is lightweight, easy to don, and generates sufficient hand closing force to assist with activities of daily living. Device efficiency was examined through a characterization of the power transmission elements, and output force production was observed to be linear in both cylindrical and pinch grasp configurations. We further show that, as a result of the synergy-inspired actuation strategy, the glove only slightly alters the distribution of forces across the fingers, compared to a natural, unassisted grasping pattern. Finally, a preliminary case study was conducted using a participant suffering from an incomplete spinal cord injury (C7). It was found that through the use of the glove, the participant was able to achieve a 50% performance improvement (from four to six blocks) in a standard Box and Block test
An Overview on Principles for Energy Efficient Robot Locomotion
Despite enhancements in the development of robotic systems, the energy economy of today's robots lags far behind that of biological systems. This is in particular critical for untethered legged robot locomotion. To elucidate the current stage of energy efficiency in legged robotic systems, this paper provides an overview on recent advancements in development of such platforms. The covered different perspectives include actuation, leg structure, control and locomotion principles. We review various robotic actuators exploiting compliance in series and in parallel with the drive-train to permit energy recycling during locomotion. We discuss the importance of limb segmentation under efficiency aspects and with respect to design, dynamics analysis and control of legged robots. This paper also reviews a number of control approaches allowing for energy efficient locomotion of robots by exploiting the natural dynamics of the system, and by utilizing optimal control approaches targeting locomotion expenditure. To this end, a set of locomotion principles elaborating on models for energetics, dynamics, and of the systems is studied
Anthropomorphic Twisted String-Actuated Soft Robotic Gripper with Tendon-Based Stiffening
Realizing high-performance soft robotic grippers is challenging because of
the inherent limitations of the soft actuators and artificial muscles that
drive them, including low force output, small actuation range, and poor
compactness. Despite advances in this area, realizing compact soft grippers
with high dexterity and force output is still challenging. This paper explores
twisted string actuators (TSAs) to drive a soft robotic gripper. TSAs have been
used in numerous robotic applications, but their inclusion in soft robots has
been limited. The proposed design of the gripper was inspired by the human
hand. Tunable stiffness was implemented in the fingers with antagonistic TSAs.
The fingers' bending angles, actuation speed, blocked force output, and
stiffness tuning were experimentally characterized. The gripper achieved a
score of 6 on the Kapandji test and recreated 31 of the 33 grasps of the Feix
GRASP taxonomy. It exhibited a maximum grasping force of 72 N, which was almost
13 times its own weight. A comparison study revealed that the proposed gripper
exhibited equivalent or superior performance compared to other similar soft
grippers.Comment: 19 pages, 15 figure
Wearable haptic systems for the fingertip and the hand: taxonomy, review and perspectives
In the last decade, we have witnessed a drastic change in the form factor of audio and vision technologies, from heavy and grounded machines to lightweight devices that naturally fit our bodies. However, only recently, haptic systems have started to be designed with wearability in mind. The wearability of haptic systems enables novel forms of communication, cooperation, and integration between humans and machines. Wearable haptic interfaces are capable of communicating with the human wearers during their interaction with the environment they share, in a natural and yet private way. This paper presents a taxonomy and review of wearable haptic systems for the fingertip and the hand, focusing on those systems directly addressing wearability challenges. The paper also discusses the main technological and design challenges for the development of wearable haptic interfaces, and it reports on the future perspectives of the field. Finally, the paper includes two tables summarizing the characteristics and features of the most representative wearable haptic systems for the fingertip and the hand
Hierarchical fibrous structures for muscle-inspired soft-actuators:A review
Inspired by Nature, one of the most ambitious challenge in soft robotics is to design actuators capable of reaching performances comparable to the skeletal muscles. Considering the perfectly balanced features of natural muscular tissue in terms of linear contraction, forceâtoâweight ratio, scalability and morphology, scientists have been working for many years on mimicking this structure. Focusing on the biomimicry, this review investigates the stateâofâtheâart of synthetic fibrous, muscleâinspired actuators that, aiming to enhance their mechanical performances, are hierarchically designed from the nanoscale up to the macroscale. In particular, this review focuses on those hierarchical fibrous actuators that enhance their biomimicry employing a linear contraction strategy, closely resembling the skeletal muscles actuation system. The literature analysis shows that bioinspired artificial muscles, developed up to now, only in part comply with skeletal ones. The manipulation and control of the matter at the nanoscale allows to realize ordered structures, such as nanofibers, used as elemental actuators characterized by high strains but moderate force levels. Moreover, it can be foreseen that scaling up the nanostructured materials into microâ and macroscale hierarchical structures, it is possible to realize linear actuators characterized by suitable levels of force and displacement
Stretchable organic optoelectronic sensorimotor synapse
Emulation of human sensory and motor functions becomes a core technology in bioinspired electronics for next-generation electronic prosthetics and neurologically inspired robotics. An electronic synapse functionalized with an artificial sensory receptor and an artificial motor unit can be a fundamental element of bioinspired soft electronics. Here, we report an organic optoelectronic sensorimotor synapse that uses an organic optoelectronic synapse and a neuromuscular system based on a stretchable organic nanowire synaptic transistor (s-ONWST). The voltage pulses of a self-powered photodetector triggered by optical signals drive the s-ONWST, and resultant informative synaptic outputs are used not only for optical wireless communication of human-machine interfaces but also for light-interactive actuation of an artificial muscle actuator in the same way that a biological muscle fiber contracts. Our organic optoelectronic sensorimotor synapse suggests a promising strategy toward developing bioinspired soft electronics, neurologically inspired robotics, and electronic prostheses.
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