Quantitative X-ray maps of composition from a chlorite, K-white mica, albite, quartz and garnet bearing thin section from a Sambagawa blueschist facies metapelite were combined with a multiequilibrium calculation method to calculate a P-T-Fe 3+ /Fe 2+-deformation map at the millimetre scale. The studied sample was chosen because elongated chlorite crystallization tails (pressure shadows) rimmed by phengite are present, which is an appropriate assemblage for the quantification of the P-T evolution. Chlorite temperature and Fe 3+ content maps were calculated by successive iterations for each pixel analysis of Fe 3+ until convergence of the four chlorite-quartz-H 2 O equilibria that can be written using the Fe-and Mg-amesite, clinchlore, daphnite and sudoite chlorite end-members. The calculated map of Fe 2+ /Fe 3+ in chlorite is in good qualitative agreement with the in situ mapping of this ratio using XANES (X-ray absorption near edge structure) techniques. The temperature map indicates that high temperature chlorite zones with low Fe 3+ contents alternate with lower temperature zones and higher Fe 3+ contents in the crystallization tail. Late fractures perpendicular to the elongation axis of the tail are filled by very low temperature chlorite (<250°C) showing Fe 3+ /Fe total up to 0.4. Groups of chlorite and mica pixels were then identified based on compositional and structural criteria, and a P-Tdeformation map was calculated using representative analyses of these groups. The calculated P-Tdeformation map suggests that in contrast to chlorite, the composition of most mica did not change significantly during exhumation. Mica reequilibrated in late EW shear bands only. EW shearing was already active at 0.1 GPa, 500°C, which corresponds to the peak temperature (and probably pressure) conditions, at reduced redox conditions. The intensity of deformation probably decreased with decrease in temperature to $350-400°C. At this temperature, a second main deformation event corresponding to a further EW stretching occurred and was still active below 250°C and more oxidizing conditions. These results indicate that the scale at which P-T data can be obtained is now close to the scale of observation of structural geologists. A close link between deformation and mineral reaction is therefore possible at the microscopic scale, which provides information about the relationship between deformation and mineral reactivity, the modalities of deformation with time and the P-T conditions at which it occurred.

International audienceXMapTools is a MATLAB©-based graphical user interface program for electron microprobe X-ray image processing, which can be used to estimate the pressure-temperature conditions of crystallization of minerals in metamorphic rocks. This program (available online at http://www.xmaptools.com) provides a method to standardize raw electron microprobe data and includes functions to calculate the oxide weight percent compositions for various minerals. A set of external functions is provided to calculate structural formulae from the standardized analyses as well as to estimate pressure-temperature conditions of crystallization, using empirical and semi-empirical thermobarometers from the literature. Two graphical user interface modules, Chem2D and Triplot3D, are used to plot mineral compositions into binary and ternary diagrams. As an example, the software is used to study a high-pressure Himalayan eclogite sample from the Stak massif in Pakistan. The high-pressure paragenesis consisting of omphacite and garnet has been retrogressed to a symplectitic assemblage of amphibole, plagioclase and clinopyroxene. Mineral compositions corresponding to $165,000 analyses yield estimates for the eclogitic pressure-temperature retrograde path from 25 kbar to 9 kbar. Corresponding pressure- temperature maps were plotted and used to interpret the link between the equilibrium conditions of crystallization and the symplectitic microstructures. This example illustrates the usefulness of XMapTools for studying variations of the chemical composition of minerals and for retrieving information on metamorphic conditions on a microscale, towards computation of continuous pressure-temperature-and relative time path in zoned metamorphic minerals not affected by post-crystallization diffusion

Silicon-based materials have widespread application as biophysical tools and biomedical devices. Here we introduce a biocompatible and degradable mesostructured form of silicon with multiscale structural and chemical heterogeneities. The material was synthesized using mesoporous silica as a template through a chemical-vapor-deposition process. It has an amorphous atomic structure, an ordered nanowire-based framework, and random submicrometre voids, and shows an average Young’s modulus that is 2–3 orders of magnitude smaller than that of single crystalline silicon. In addition, we used the heterogeneous silicon mesostructures to design a lipid-bilayer-supported bioelectric interface that is remotely controlled and temporally transient, and that permits non-genetic and subcellular optical modulation of the electrophysiology dynamics in single dorsal root ganglia neurons. Our findings suggest that the biomimetic expansion of silicon into heterogeneous and deformable forms can open up opportunities in extracellular biomaterial or bioelectric systems.

Nowadays, millimeter scale power sources are key devices for providing autonomy to smart, connected and miniaturized sensors. However, until now, planar solid state microbatteries do not yet exhibit a sufficient surface energy density. In that context, architectured 3D (3 dimensional) microbatteries appear therefore to be a good solution to improve the material mass loading while keeping small the footprint area. Beside the design itself of the 3D microbaterry, one important technological barrier to address is the conformal deposition of thin films (lithiated or not) on 3D structures. For that purpose, Atomic Layer Deposition (ALD) technology is a powerful technique that enable conformal coatings of thin film on complex substrate. In this paper, an original, robust and highly efficient 3D scaffold is proposed to significantly improve the geometrical surface of miniaturized 3D microbattery.Four functional layers composing the 3D lithium ion microbattery stacking has been Received: ((will be filled in by the editorial staff))Revised: ((will be filled in by the editorial staff))