ERC FUNDED PROJECTS

The idea of mechanical actuator based on intrinsic material properties of liquid-crystalline elastomers (rather than complex engineering of interacting components) has been understood for 20+ years. The remarkable characteristics of LCE actuation (fully reversible action; large-amplitude, with a stroke of 5%-300%; stress-strain-speed response almost exactly matching the human muscle) make it highly attractive in biomedical engineering, robotics, smart textiles, and other fields. Yet, there is a profound difficulty (bottleneck), which remains the reason why this concept has not found its way into any practical devices & applications. LCE actuation requires alignment (monodomain structure) of the local anisotropy in the permanently crosslinked polymer network - which has been impossible to achieve in any useful large-scale configuration except the flat film, due to the unavoidable restrictions of two competing processes: orientational alignment and network crosslinking. Recently, we made a breakthrough, developing LCE vitrimers (polymer networks covalently crosslinked by a bond-exchange reaction). Vitrimers are much more stable than other transient elastomer networks, allow easy thermal re-moulding (making the material fully renewable), and permit molding of complex shapes with intricate local alignment (which are impossible in traditional elastomers). This project will bridge from the concept to technology, tuning the material design for robust nematic LCE vitrimers, imparting photo-actuation capacity with a controlled wavelength, and finally utilising them in practical-engineering actuator applications where the reversible mechanical action is stimulated by light, solvent exposure, or more traditionally - heat. These applications include (but not limited to): continuous spinning light-driven motor, tactile dynamic Braille display, capillary pump and toggle flow switch for microfuidics, active textile fibre, and heliotracking filament that always points at the Sun.

2 012 136 €

Start date: 2018-10-01, End date: 2023-09-30

The onset of the systematic consumption of marine resources is thought to mark a turning point for the hominin lineage. To date, this onset cannot be traced, since classic isotope markers are not preserved beyond 50 - 100 ky. Aquatic food products are essential in human nutrition as the main source of polyunsaturated fatty acids in hunter-gatherer diets. The exploitation of marine resources is also thought to have reduced human mobility and enhanced social and technological complexification. Systematic aquatic food consumption could well have been a distinctive feature of Homo sapiens species among his fellow hominins, and has been linked to the astonishing leap in human intelligence and conscience. Yet, this hypothesis is challenged by the existence of mollusk and marine mammal bone remains at Neanderthal archeological sites. Recent work demonstrated the sensitivity of Zn isotope composition in bioapatite, the mineral part of bones and teeth, to dietary Zn. By combining classic (C and C/N isotope analyses) and innovative techniques (compound specific C/N and bulk Zn isotope analyses), I will develop a suite of sensitive tracers for shellfish, fish and marine mammal consumption. Shellfish consumption will be investigated by comparing various South American and European prehistoric populations from the Atlantic coast associated to shell-midden and fish-mounds. Marine mammal consumption will be traced using an Inuit population of Arctic Canada and the Wairau Bar population of New Zealand. C/N/Zn isotope compositions of various aquatic products will also be assessed, as well as isotope fractionation during intestinal absorption. I will then use the fully calibrated isotope tools to detect and characterize the onset of marine food exploitation in human history, which will answer the question of its specificity to our species. Neanderthal, early modern humans and possibly other hominin remains from coastal and inland sites will be compared in that purpose.

1 361 991 €

Start date: 2019-03-01, End date: 2024-02-29

The aim of this project is to develop and to demonstrate a novel theoretical framework devoted to rationalizing the formulation of composite electrodes containing next-generation material chemistries for high energy density secondary batteries. The framework will be established through the combination of discrete particle and continuum mathematical models within a multiscale computational workflow integrating the individual models and mimicking the different steps along the electrode fabrication process, including slurry preparation, drying and calendering. Strongly complemented by dedicated experimental characterizations which are devoted to its validation, the goal of this framework is to provide insights about the impacts of material properties and fabrication process parameters on the electrode mesostructures and their corresponding correlation to the resulting electrochemical performance. It targets self-organization mechanisms of material mixtures in slurries by considering the interactions between the active and conductive materials, solvent, binders and dispersants and the relationship between the materials properties such as surface chemistry and wettability. Optimal electrode formulation, fabrication process and the arising electrode mesostructure can then be achieved. Additionally, the framework will be integrated into an online and open access infrastructure, allowing predictive direct and reverse engineering for optimized electrode designs to attain high quality electrochemical performances. Through the demonstration of a multidisciplinary, flexible and transferable framework, this project has tremendous potential to provide insights leading to proposals of new and highly efficient industrial techniques for the fabrication of cheaper and reliable next-generation secondary battery electrodes for a wide spectrum of applications, including Electric Transportation.

1 976 445 €

Start date: 2018-04-01, End date: 2023-03-31

Severe droughts in Amazonia in 2005 and 2010 caused widespread loss of carbon from the terrestrial biosphere. This loss, almost twice the annual fossil fuel CO2 emissions in the EU, suggests a large sensitivity of the Amazonian carbon balance to a predicted more intense drought regime in the next decades. This is a dangerous inference though, as there is no scientific consensus on the most basic metrics of Amazonian carbon exchange: the gross primary production (GPP) and its response to moisture deficits in the soil and atmosphere. Measuring them on scales that span the whole Amazon forest was thus far impossible, but in this project I aim to deliver the first observation-based estimate of pan-Amazonian GPP and its drought induced variations. My program builds on two recent breakthroughs in our use of stable isotopes (13C, 17O, 18O) in atmospheric CO2: (1) Our discovery that observed δ¹³C in CO2 in the atmosphere is a quantitative measure for vegetation water-use efficiency over millions of square kilometers, integrating the drought response of individual plants. (2) The possibility to precisely measure the relative ratios of 18O/16O and 17O/16O in CO2, called Δ17O. Anomalous Δ17O values are present in air coming down from the stratosphere, but this anomaly is removed upon contact of CO2 with leaf water inside plant stomata. Hence, observed Δ17O values depend directly on the magnitude of GPP. Both δ¹³C and Δ17O measurements are scarce over the Amazon-basin, and I propose more than 7000 new measurements leveraging an established aircraft monitoring program in Brazil. Quantitative interpretation of these observations will break new ground in our use of stable isotopes to understand climate variations, and is facilitated by our renowned numerical modeling system “CarbonTracker”. My program will answer two burning question in carbon cycle science today: (a) What is the magnitude of GPP in Amazonia? And (b) How does it vary over different intensities of drought?

2 269 689 €

Start date: 2015-09-01, End date: 2020-08-31