Glove shows its true colors: Identifies poisons on contact

The sensor glove turns blue in the presence of hazardous substances. Credit: © Fraunhofer EMFT

Security takes top priority in laboratories and in production. In the future, employees exposed to risks will only have to put on a glove in order to receive a toxic substance warning: This textile identifi es poisonous substances, and points them out immediately.

Employees in chemical production, the semiconductor industry or in laboratories are frequently exposed to harmful substances. The problem: Many of these aggressive substances are imperceptible to human senses, which makes handling them so risky. That's why there is a broad range of solutions that employers can use to protect their staff from hazardous substances -- from highly sensitive measuring equipment to heat imaging cameras. Soon, this spectrum will be enhanced by one more clever solution that is easy to handle, and that dispenses with a power supply. Researchers at the Fraunhofer Research Institution for Modular Solid State Technologies EMFT in Regensburg have engineered a glove that recognizes if toxic substances are present in the surrounding air.

The protective glove is equipped with custom-made sensor materials and indicates the presence of toxic substances by changing colors. In this regard, the scientists adapted the materials to the corresponding analytes, and thus, the application. The color change -- from colorless (no toxic substance) to blue (toxic substance detected), for example -- warns the employee immediately. "By synthesizing the adapted color sensor materials, we can detect gases like carbon monoxide, for example, or hydrogen sulfide. Still, this protective gear represents only one potential area of application. Sensor materials could also be deployed for the quick detection of leaks in gas lines," explains Dr. Sabine Trupp, head of the Fraunhofer EMFT Sensor Materials group. The researcher and her team will exhibit this occupational safety article of clothing at Fraunhofer's joint exhibition booth (Hall 12, Booth 537) at the Sensor + Test trade show in Nuremberg from May 14 to 16.

Tailor-made indicator dyes

The warning signal is triggered by an indicator dye integrated into the glove that reacts to the presence of analytes, in this case, the toxic substances. The experts at EMFT used a variety of techniques in order to furnish textiles with sensor-activated dyes. The sensor-activated dyes are applied to the clothing with the customary dye and print process, for example, by affixing them in an immersion bath. Previously, the researchers used targeted chemical modification to adapt the color molecules to the fiber properties of the respective textile. Alternatively, the textiles can also be coated with sensor particles that are furnished with sensor dyes. For this purpose, the scientists integrated the dye molecules either into commercial pigments or they built them up on an entirely synthetic basis. The pigments are then manufactured according to the customary textile finishing process, for instance, the sensor particles are also suitable for silkscreening. "Which version we opt for depends on the requirements of the planned application," says Trupp.

The challenge lies foremost in the tailored development of sensor dyes. "The dye molecule must detect a specific analyte in a targeted manner -- only then will a chemical reaction occur. Moreover, the dye must adhere securely; it cannot disappear due to washing. We aim for the customer's preferences in the color selection as well. All of these aspects must be kept in mind when developing the molecule and pigment properties," explains Trupp.

The expert already has new ideas about how the solution could be developed further. For example, a miniaturized sensor module, integrated into textiles, could record toxic substances, store the measurement data and even transmit them to a main unit. This way, you could document how frequently an individual within a hazardous environment was exposed to poisonous concentrations over a longer period of time.

The researchers also envision other potential applications in the foodstuffs industry: In the future, color indicator systems integrated into foils or bottle closures are intended to make the quality status of the packaged foods visible. Because the sell-by date does not represent a guarantee of any kind. Foodstuffs may often spoil prematurely -- unnoticed by the consumer -- due to a packaging error, or in the warehousing, or due to disruptions in the refrigeration chain. Oil-based and fat-containing products are specifically prone to this, as are meats, fish and ready meals.

Source: Fraunhofer-Gesellschaft

New laws threaten Brazil's unique ecosystems

Brazil's globally significant ecosystems could be exposed to mining and dams if proposals currently being debated by the Brazilian Congress go ahead, according to researchers publishing in the journal Science this week. Credit: Alexander C. Lees

Brazil´s globally significant ecosystems could be exposed to mining and dams if proposals currently being debated by the Brazilian Congress go ahead, according to researchers publishing in the journal Science this week.

The new report by a group of Brazilian and British researchers comes in the wake of Brazil´s recent presidential elections. It warns that new legislation could pose a serious threat to protected areas, weakening Brazil's international status as an environmental leader.

One of the proposals of particular concern is the call to open up 10% of the most strictly protected areas to mining. In a new analysis, the research shows that at least 20% of all Brazil´s most strictly protected areas and reserves for indigenous people overlap with areas that have been registered as under consideration for mining. In addition, many of the river systems associated with protected areas will be influenced by the construction of large hydroelectric dams.

The threat that this mining and hydropower poses to Brazil's ecosystems is not trivial. Areas of registered interest for mining include 34,117 km2 that are currently classified as strictly protected areas -- including National Parks, Biological Reserves and Wildlife Refuges. This is equivalent to an area the size of Switzerland. The situation is worse for indigenous lands, 28% of which, or 281,443 km2, overlap with areas of registered mining interest -- an area larger than the whole of the UK or the state of São Paulo.

In recent years Brazil has enjoyed increasing recognition as a world leader in combatting environmental destruction. Brazil´s protected area network is the largest in the world, while improved environmental governance in private lands has contributed to an 80% reduction in the rate of deforestation in the Brazilian Amazon over the last decade. Yet these new proposals could threaten these recent successes and undermine Brazil's reputation.

Dr Joice Ferreira, a scientist at Brazil´s agricultural research institute, Embrapa, and lead author of the study, said: "The purpose of this analysis is not to say that Brazil´s development should not benefit from its abundant natural resources, but that we should not squander our hard-won record of success and leadership in favor of fast-tracked and poorly planned development projects that leave a long legacy of environmental damage. It is possible to manage our development in a more sustainable way."

Co-author Dr Jos Barlow, a researcher at Lancaster University and a visiting professor in Brazil, said: "Rather than exploiting protected areas for short-term gains, Brazil should treasure them for the long-term benefits they can provide to society. The recent water shortages in the south east of Brazil emphasize the importance of protecting native vegetation across the country."

The authors of the study also warn that the proposals for minimizing and mitigating the environmental damage of large-scale development projects are so inadequate that even if only a fraction of these mining concessions were approved then the impacts could be enormous, especially in Brazil´s most threatened ecosystems.

Dr. Luiz Aragão a co-author of the study from Brazil´s federal space agency, INPE and the University of Exeter said: "Our concern is that even if the proposed mitigation actions were put in place they are oversimplified because they fail to take account of the indirect effects of mega-projects.
"These projects can involve thousands of workers and lead to rapid local population growth. This, combined with new roads and access routes, is a recipe for the emergence of new deforestation frontiers." explains Luiz.

The study highlights the fact that these worrying changes reflect an important shift in the support shown by Brazil´s federal government to environmental protection. These concerns come on the back of other recent changes, including the partial dismantling of Brazil´s protected area system to make way for development -- with some 44,100 km2 lost since 2008 due to downsizing or abolishment -- and the weakening of the Forest Code that gave an amnesty to landowners who deforested illegally in the past.

"Beyond the conservation and stewardship of its own biodiversity and environmental resources, so vital to the wellbeing of its citizens, Brazil plays a vital role in motivating and supporting the adoption of more sustainable development trajectories around the world," said Toby Gardner, of Stockholm Environment Institute, one of the authors of the study who has worked in the country for more than a decade. "Yet this standing is now in jeopardy."

Dr Joice Ferreira said: "The newly elected government has the chance to set the record straight and point Brazil firmly on a path of sustainable development. The authors of this report call on President Dilma and her government to ensure that individual development initiatives are subject to a comprehensive, socially inclusive, evidence-based and long-term cost-benefit analysis that compares potential environmental and social impacts against alternative development options. And also to ensure that Brazil´s renowned protected area network is given the resources it needs to manage our ecosystems sustainably.

"Above all we ask the Government to guarantee that important decisions regarding the management of Brazil´s natural resources involve the full and democratic participation of Brazilian society."

Source: Lancaster University