746 research outputs found
Autism and Externalizing Behaviors: Attachment as a Protective Factor
Children with autism spectrum disorder (ASD) exhibit externalizing behaviors at a higher rate when compared to their typically developing (TD) counterparts (Bauminger, Solomon, & Rogers, 2010; Gray, Keating, Taffe, & Brereton, 2012). Numerous longitudinal and cross-sectional studies assert that attachment is one of the most salient predictors of childhood externalizing behaviors (e.g., Green and Goldwyn, 2002). Despite this, little research has examined the relation between attachment and externalizing behaviors in children with ASD. This study investigated the extent to which high levels of attachment buffer the symptoms of externalizing behaviors in children with ASD, potentially informing future interventions. In addition, this study examined the relation between attachment and child externalizing behaviors. Participants included 10 TD children and 7 children with ASD (52.9% male; 47.1% female) between the ages of 3 years and 6 years 11 months (Mean age =61.53 months, SD = 16.28 months). Parent self-reports were used to evaluate the level of parent-child attachment and child externalizing behaviors. Parents of children with ASD had significantly greater reported overall child externalizing behaviors (p = .027). No significant differences were observed in parent reported attachment levels and attachment was not significantly associated with externalizing behavior. Attachment did not significantly moderate the relation between diagnostic status and externalizing behaviors. Given the small sample size and low statistical power of this study, these results may under-estimate the relation between attachment and externalizing behavior in children with ASD. While the results of this study did not support attachment as a protective factor for parents of children with ASD, attachment x diagnostic status did account for 17% of additional variation in externalizing behavior. Plotting of regression slopes depicted a visible inverse trend between attachment and externalizing behavior among parents with ASD children but not TD children. These findings suggest the relation between parent-child attachment and externalizing behaviors is more evident among ASD participants. Therefore, children with high levels of externalizing behaviors, particularly those with ASD, could benefit from interventions aimed at strengthening attachment within the parent-child dyad
Textile-based active-sensory skins
Future generations of robots will include systems constructed from soft, conformable materials with embedded function for wearable and/or human-robot interaction applications. In particular, active textiles may be employed in applications, such as wearable computing, proprioceptive feedback, or load augmentation while potentially exploiting many textile manufacturing processes that are already widespread. In this discussion, a preliminary prototype of a robotic fabric with embedded actuation and sensing will be presented. By attaching the same robotic fabric to a soft body in different configurations, unique motions (such as compression and bending) have been demonstrated. The prototype incorporates shape-memory alloy (SMA) wires stitched onto a fabric base to actuate the fabric. Custom-designed hyperelastic strain sensors, stitched alongside the SMA wire, were used to determine the displacement of the fabric and to qualitatively differentiate between the compressive and bending motions demonstrated. In addition, a parametric study was performed to better understand SMA-fabric interactions. Parameters that were studied include elasticity of the fabric base, stitch length, stitch thread elasticity, and programmed coil diameter. Empirical trends for each parameter will be presented in the context of end-to-end displacement and force generation, as well as resulting design guidelines for tailoring robotic fabrics towards various applications. Finally, this discussion will highlight the manufacturability of robotic fabrics that employ thread-like actuators and sensors via common techniques such as sewing and stitching
Scalable manufacturing processes with soft materials
The emerging field of soft robotics will benefit greatly from new scalable manufacturing techniques for responsive materials. Currently, most of soft robotic examples are fabricated one-at-a-time, using techniques borrowed from lithography and 3D printing to fabricate molds. This limits both the maximum and minimum size of robots that can be fabricated, and hinders batch production, which is critical to gain wider acceptance for soft robotic systems. We have identified electrical structures, including both resistance-based sensors and inter connects, as a critical starting point for developing more complex soft robotic structures. In this talk, we present our study on scalable manufacturing processes with soft materials, focusing on direct patterning of micro channels with laser ablation and layer-to-layer bonding of hyper elastic polymer substrates. The use of direct laser fabrication has three major advantages. First, it allows for rapid design iterations, because molds are not required. Second, it is scalable to larger substrates than mold-based approaches, because a laser-based system can pattern a continuous substrate. Third, a laser-based approach removes the challenges associated with incomplete material removal in through-layer structures that are encountered in mold-based approaches. Using this approach, we have fabricated strain gauges, layer-to-layer electrical interconnects, and comb capacitors, all by injecting liquid metal into closed microchannels embedded in polymer films
Materials for soft robotic applications
Soft robotics has been recently gaining interest and momentum, as soft, functional systems offer levels of flexibility, robustness, wearability, and safety that their rigid counterparts cannot match. To date, most soft robots are made from polymers that exhibit nonlinear behaviors and viscoelastic creep. However, the most common polymers -employed in soft robotic applications have not been critically evaluated in high-strain environments over many cycles. We have performed tension experiments on representative material samples, including stress/strain relations up to rupture and cyclic loading. We also demonstrate a unique relaxation effect in polymer systems, where material properties change significantly from the first stress cycle to the subsequent cycles. Our experimental results are useful for creating material models for soft robot designers. We demonstrate that the unique properties of soft materials cannot be captured with linear models and that failing to account for these complex effects can significantly affect the design performance
Strengthening Community Foundations - Redefining the Opportunities
Commissioned by the Council on Foundations and released in October 2003, this white paper details the findings and the implications of our study of costs and revenues at nine community foundations. Offering a new perspective for community foundation sustainability, the white paper proposes that community foundations examine their strategy and operations on a product-by-product basis, taking into account their mission-driven priorities, internal costs, customer preferences and the competing donor alternatives for each type of product or service they offer
Where should livestock graze? Integrated modeling and optimization to guide grazing management in the Cañete basin, Peru
Integrated watershed management allows decision-makers to balance competing objectives, for example agricultural production and protection of water resources. Here, we developed a spatially-explicit approach to support such management in the Cañete watershed, Peru. We modeled the effect of grazing management on three services – livestock production, erosion control, and baseflow provision – and used an optimization routine to simulate landscapes providing the highest level of services. Over the entire watershed, there was a trade-off between livestock productivity and hydrologic services and we identified locations that minimized this trade-off for a given set of preferences. Given the knowledge gaps in ecohydrology and practical constraints not represented in the optimizer, we assessed the robustness of spatial recommendations, i.e. revealing areas most often selected by the optimizer. We conclude with a discussion of the practical decisions involved in using optimization frameworks to inform watershed management programs, and the research needs to better inform the design of such programs
Design of a Small Scale Roll to Roll Device
In the soft robotics field, hyperelastic polymer films are used in conjunction with eutectic gallium indium to create flexible strain gages. However, rapid large scale manufacturing methods of such sensors have yet to be developed.
Developing new manufacturing methods will allow for researchers to build and test new soft sensor concepts faster but also pave the way for future mass-production of these sensors for consumer or industrial consumption.
One of those methods would be a Roll to Roll System (R2R) similar to those used to in the publication industry. In this context, Polyethylene terephthalate (PET) film rolls will be used as a medium upon which hyperelastic polymer films and eutectic gallium indium will be deposited on. This research paper will discuss the design of a small scale roll to roll system used in the Purdue Fabrication Laboratory.
After designing and building a scaled down R2R prototype system, we found that this system must be able to adequately control the PET web tension, and web position to ensure the accuracy of the printed of the soft sensor.
Due to an absence of a readily available and economical R2R device made specifically for soft robotics, our laboratory built one that would be able to interface with laboratory equipment and that enabled an efficient manufacturing of flexible sensors. This device will serve as a step towards the development of large scale soft robotics printing
Integrating Systems for Liquid/Substrate Characterization and Functional Printing
Gallium-Indium alloys are recently applied in fabricating soft devices, such as stretchable sensors, electric circuits, micro pumps and optics. Its printability demonstrates the possibility for a wide extension of the application. Current fabrication methods are inefficient when printing is most handled manually, and are highly dependent on material properties. There is need for a fast way to characterize material properties, and to functionally print the given shape on the substrate. This paper presents the construction of an efficiently integrated system with optical imaging and functional printing for Gallium-Indium alloys. The imaging section allows for characterization of material properties to fast and accurately determine printing parameters in printing section. A new algorithm, which extends generalized Hough Transform, is designed to determine the contact angle of sessile drops by fitting the shape based on Bashforth-Adams equation. The results are later applied in determination of featured geometry in printing. The algorithm shows relatively low errors in profiling the sessile drop shapes. However, the results are not stable for 5% of test pictures, and thus revisions are still needed. In addition, functional printing is finalized with a direct writing module and a friendly user interface. A series of the state-of-the-art algorithms are adopted in image analysis and controlling. Test printing shows its workability, flexibility and accordance to the previous work. The integrated system presents a solution for both accuracy and efficiency in Gallium-Indium alloy printing
From Insight to Action: New Directions in Foundation Evaluation
The field of philanthropy is undergoing a fundamental transition toward more performance-centered and forward-looking evaluation approaches that provide foundations and their grantees with timely information and actionable insights. Our report highlights emerging evaluation practices and identifies major trends in the field related to increasing effectiveness for both foundations and grantees. Based on nearly 100 interviews with foundation leaders and evaluators, this report represents the first step in a multi-year action initiative to develop pragmatic evaluation approaches that enable foundations, large or small, to achieve greater social impact
- …