107 research outputs found

    Integrated Circuitry to Detect Slippage Inspired by Human Skin and Artificial Retinas

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    This paper presents a bioinspired integrated tactile coprocessor that is able to generate a warning in the case of slippage via the data provided by a tactile sensor. Some implementations use different layers of piezoresistive and piezoelectric materials to build upon the raw sensor and obtain the static (pressure) as well as the dynamic (slippage) information. In this paper, a simple raw sensor is used, and a circuitry is implemented, which is able to extract the dynamic information from a single piezoresistive layer. The circuitry was inspired by structures found in human skin and retina, as they are biological systems made up of a dense network of receptors. It is largely based on an artificial retina , which is able to detect motion by using relatively simple spatial temporal dynamics. The circuitry was adapted to respond in the bandwidth of microvibrations produced by early slippage, resembling human skin. Experimental measurements from a chip implemented in a 0.35-mum four-metal two-poly standard CMOS process are presented to show both the performance of the building blocks included in each processing node and the operation of the whole system as a detector of early slippage.Ministerio de Economía y Competitividad TEC2006-12376-C02-01Gobierno de España TEC2006- 1572

    Integrated circuit interface for artificial skins

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    Artificial sensitive skins are intended to emulate the human skin to improve the skills of robots and machinery in complex unstructured environments. They are basically smart arrays of pressure sensors. As in the case of artificial retinas, one problem to solve is the management of the huge amount of information that such arrays provide, especially if this information should be used by a central processing unit to implement some control algorithms. An approach to manage such information is to increment the signal processing performed close to the sensor in order to extract the useful information and reduce the errors caused by long wires. This paper proposes the use of voltage to frequency converters to implement a quite straightforward analog to digital conversion as front end interface to digital circuitry in a smart tactile sensor. The circuitry commonly implemented to read out the information from a piezoresistive tactile sensor can be modified to turn it into an array of voltage to frequency converters. This is carried out in this paper, where the feasibility of the idea is shown through simulations and its performance is discussed.Gobierno de España TEC2006-12376-C02-01, TEC2006-1572

    Tactile on-chip pre-processing with techniques from artificial retinas

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    The interest in tactile sensors is increasing as their use in complex unstructured environments is demanded, like in tele-presence, minimal invasive surgery, robotics etc. The matrix of pressure data these devices provide can be managed with many image processing algorithms to extract the required information. However, as in the case of vision chips or artificial retinas, problems arise when the array size and the computation complexity increase. Having a look to the skin, the information collected by every mechanoreceptor is not carried to the brain for its processing, but some complex pre-processing is performed to fit the limited throughput of the nervous system. This is specially important for high bandwidth demanding tasks. Experimental works report that neural response of skin mechanoreceptors encodes the change in local shape from an offset level rather than the absolute force or pressure distributions. This is also the behavior of the retina, which implements a spatio-temporal averaging. We propose the same strategy in tactile preprocessing, and we show preliminary results when it faces the detection of the slip, which involves fast real-time processing.Ministerio de Ciencia y Tecnología TIC2003 - 09817-C0

    Filtration of Biopolymer PHB Particles Loaded With Synthetic Musks Does Not Cause Significant Bioaccumulation in Marine Mussels

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    [Abstract] The role of the biopolymer polyhydroxybutyrate (PHB, <250 µm) as a vehicle of a synthetic musks mixture (celestolide, galaxolide, tonalide, musk xylene, musk moskene and musk ketone) to Mytilus galloprovincialis was investigated. For 30 days, virgin PHB, virgin PHB+musks (6.82 µg g-1) and weathered PHB+musks, were daily spiked into tanks containing mussels, followed by a 10-day depuration period. Water and tissues samples were collected to measure exposure concentrations and accumulation in tissues. Mussels were able to actively filter microplastics in suspension but the concentration of the musks found in tissues (celestolide, galaxolide, tonalide) were markedly lower than the spiked concentration. Estimated Trophic Transfer Factors suggest that PHB will only play a minor role on musks accumulation in marine mussels, even if our results suggest a slightly extended persistence in tissues of musks loaded to weathered PHB.We thank AIMPLAS for in-kind supplying customized PHB polymers. This study was funded by AEI/10.13039/501100011033 (Spanish Government) through the ARPA-ACUA (CTM2016–77945-C3) and RISBIOPLAS (PID2019–108857RB-C32) project

    Optimized protocol and template for monitoring floating macrolitter by scientific observers onboard research vessels

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    In 2007 the Spanish Institute of Oceanography (IEO) established for the first time the group of Apex Predators (marine mammals, seabirds and turtles) observers during a campaign to evaluate pelagic fisheries in the Bay of Biscay (PELACUS 07). This campaign was performed onboard the RV Thalassa, where researchers from the University of La Rochelle carried out the campaign PELGAS, which included apex predator surveys too. Therefore, the same protocol used by French researchers was applied for PELACUS with the aim of facilitating data collection and sharing. This protocol was also adopted by the Spanish research institute AZTI during their campaigns JUVENA and BIOMAN. Since then floating macro litter was incorporated also to the list of observations to be reported by observers to optimize marine debris surveys and allow for an estimation of its density. In the frame of the CleanAtlantic project (Tackling marine litter in the Atlantic Area) the protocol and templates used for recording floating litter were further adapted and improved so that they could be used as a common tool for any observer regardless the specificities of R/V and institutions, and also to facilitate the work of the observers. Thus, the optimized and English-translated protocols and datasheets for apex predators and marine litter recording are presented in the next sections. This work was carried out under the Work Package 5.2, whose final aim is to reinforce and support the monitoring of marine litter in the framework of the Marine Strategy Framework Directive (MSFD)

    Tactile retina for slip detection

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    The interest in tactile sensors is increasing as their use in complex unstructured environments is demanded, like in telepresence, minimal invasive surgery, robotics etc. The array of pressure data provided by these devices can be treated with different image processing algorithms to extract the required information. However, as in the case of vision chips or artificial retinas, problems arise when the array size and the computation complexity increase. Having a look at the skin, the information collected by every mechanoreceptor is not sent to the brain for its processing, but some complex pre-processing is performed to fit the limited throughput of the nervous system. This is specially important for high bandwidth demanding tasks. Experimental works report that neural response of skin mechanoreceptors encodes the change in local shape from an offset level rather than the absolute force or pressure distributions. Something similar happens in the retina, which implements a spatio-temporal averaging. We propose the same strategy in tactile preprocessing, and we show preliminary results illustrated for the case of slip detection, which is certainly demanding in computing requirements.Ministerio de Ciencia y Tecnología TIC2003- 09817-C0

    Bioaccumulation of UV filters in Mytilus galloprovincialis mussel

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    This is the postprint (accepted manuscript) version of the article published in Chemosphere https://doi.org/10.1016/j.chemosphere.2017.09.144In this study the bioaccumulation kinetics of organic UV filters, such as 4-MBC, BP-3, BP-4, OC and OD-PABA in wild Mytilus galloprovincialis mussels was investigated. The uptake and accumulation of waterborne 4-MBC, BP-4 and OC was very rapid, and after only 24 h of exposure to 1 μg L−1, the tissular concentrations were 418, 263 and 327 μg kg−1d.w., respectively. The kinetics of bioaccumulation of BP-4 and OC significantly fitted to an asymptotic model with BCF values of 905 L kg−1 and 2210 L kg−1, respectively. Measured bioaccumulation of the hydrophilic chemical BP-4 was much higher than predicted by Kow-based bioconcentration models, which would lead to a marked underestimation of actual risk. On the other hand, the patterns of uptake found for BP-3 and OD-PABA suggest biotransformation ability of mussels for these two chemicalshis work was financed by the Galician Government (Xunta de Galicia) through the Research Project 10MDS700006PR and GRC2013-020, by the Spanish Government through the Research Projects CTM2016-77945-C3 and CTM2014-56628-C3-2-R, and FEDER/ERDF. The first two authors were granted with an FPU and an FPI fellowships, respectively, from the Spanish GovernmentS

    Impact of regulated and emerging pollutants and microplastics in marine ecosystems (IMPACTA project)

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    Marine ecosystems are nowadays subjected to a massive input of synthetic chemicals from everywhere. Unfortunately only a small portion of them is being monitored, and it is necessary to identify which pollutants can produce adverse impacts in the marine environment. IMPACTA project (CTM2013-48194-C3) is characterizing the distribution of regulated and emerging contaminants and microplastics in marine sediments, and evaluating the biological effects that they can cause (sing sublethal embryotoxicity tests, endocrine disruption and biomarkers). Sensitive and selective analytical methods are being developed and validated for pharmaceuticals, perfluorinated compounds, organophosphorus pesticides, triazines, personal care products, nonylphenols and alkylated PAHs in sediments. Thus, relevant pollutants present in coastal and offshore areas will be identified. Furthermore potential toxic effects of the contaminants present in coastal sediments are being assessed through embryotoxicity bioassays and also the biological effects on different marine species as a consequence of their exposition to specific compounds. Another relevant contribution of this project will be the assessment of the impact of micro-plastics, first time in the Spanish coastal areas. Their potential toxic effects and their role in the transference of pollutants in the marine environment are being assessed. The concentration and composition of microplastics in sediments and demersal fish stomachs are being characterized, and their potential biological effects on marine invertebrates are also being investigated
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