129 research outputs found
A Fullerene-platinum Complex for Direct Functional Patterning of Single Metal Atom-embedded Carbon Nanostructures
No full textThe development of patterning materials (“resists”) at the nanoscale involves two distinct trends: one is toward high sensitivity and resolution for miniaturization, the other aims at functionalization of the resists to realize bottom-up construction of distinct nanoarchitectures. Patterning of carbon nanostructures, a seemingly ideal application for organic functional resists, has been highly reliant on complicated pattern transfer processes because of a lack of patternable precursors. Herein, we present a fullerene–metal coordination complex as a fabrication material for direct functional patterning of sub-10 nm metal-containing carbon structures. The attachment of one platinum atom per fullerene molecule not only leads to significant improvement of sensitivity and resolution but also enables stable atomic dispersion of the platinum ions within the carbon matrix, which may gain fundamentally new interest in functional patterning of hierarchical carbon nanostructures
Gaze awareness improves collaboration efficiency in a collaborative assembly task
No full textIn building human robot interaction systems, it would be helpful to understand how humans collaborate, and in particular, how humans use others’ gaze behavior to estimate their intent. Here we studied the use of gaze in a collaborative assembly task, where a human user assembled an object with the assistance of a human helper. We found that the being aware of the partner’s gaze significantly improved collaboration efficiency. Task completion times were much shorter when gaze communication was available, than when it was blocked. In addition, we found that the user’s gaze was more likely to lie on the object of interest in the gaze-aware case than the gaze-blocked case. In the context of human-robot collaboration systems, our results suggest that gaze data in the period surrounding verbal requests will be more informative and can be used to predict the target object.</p
Gaze-controlled Robot-assisted Painting in Virtual Reality for Upper-limb Rehabilitation
No full textStroke is the leading cause of adult disability. Robot-assisted rehabilitation systems show great promise for motor recovery after a stroke. In this work, we present a gazecontrolled robotic system for upper limb rehabilitation. Subjects perform a painting task in virtual reality. We designed a novel and challenging painting task to encourage motivation and engagement, as these are critical factors in treatment efficacy. Because the robotic system can be programmed to provide varying amounts of assistance or resistance to the subject, it can be applied to a wide range of patients at different phases of recovery. We describe here the system configured in two modes: resistive control and hierarchical control. The former is designed for later stages of recovery, where the patient's impaired limb has recovered some function. It can be configured to provide varying degrees of resistance by adjusting the properties of an admittance controller. The latter targets patients in more acute phases, where the impaired limb is less responsive. It provides a combination of assistive and corrective control. We pilot tested our system on 10 able-bodied subjects. Our results show that the system can provide varying degrees of resistive control, and that the integration of high level control modulated by gaze can improve engagement. These results suggest that the system may provide a more engaging environment for a wide range of rehabilitative therapies than currently available.</p
Focal length modulation based on a metallic slit surrounded with grooves in curved depths
No full textUser Engagement Correlates Better with Behavioral than Physiological Measures in a Virtual Reality Robotic Rehabilitation System
No full textRobotic systems to assist with movement rehabil-itation are transitioning from providing fixed pre-programmed assistance towards adaptive challenge-oriented strategies that present patients with tasks that are demanding yet achiev-able. This promotes active engagement, which is crucial for stimulating neural plasticity and promoting recovery. While it has been well established that varying the challenge level can affect user engagement, measuring engagement during task performance has received less attention. To investigate this issue, we developed a virtual reality (VR) robotic system for upper limb rehabilitation using a line-tracing task that measures physiological and behavioral signals. Challenge level can be modulated by introducing force noise disturbance. We con-ducted a preliminary study on 12 participants, measuring user engagement and physiological/behavioral signals at different noise (challenge) levels. Our findings align with the predictions of flow channel theory. Engagement peaks at an intermediate challenge level. While past work considered only physiological measures, our results reveal that behavioral measures are better correlated with user engagement. Physiological measures correlate better with arousal. This work takes a step toward systems that dynamically adapt task parameters to optimize user engagement.</p
- …
