Front instabilities in evaporatively dewetting nanofluids

Various experimental settings that involve drying solutions or suspensions of nanoparticles -- often called nanofluids -- have recently been used to produce structured nanoparticle layers. In addition to the formation of polygonal networks and spinodal-like patterns, the occurrence of branched structures has been reported. After reviewing the experimental results we use a modified version of the Monte Carlo model first introduced by Rabani et al. [Nature 426, 271 (2003)] to study structure formation in evaporating films of nanoparticle solutions for the case that all structuring is driven by the interplay of evaporating solvent and diffusing nanoparticles. After introducing the model and its general behavior we focus on receding dewetting fronts which are initially straight but develop a transverse fingering instability. We analyze the dependence of the characteristics of the resulting branching patterns on the driving chemical potential, the mobility and concentration of the nanoparticles, and the interaction strength between liquid and nanoparticles. This allows us to understand the underlying instability mechanism.Comment: 35 pages, 28 figure

GaN wire-based Langmuir–Blodgett films for self-powered flexible strain sensors

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Patterning Strategy for Monoelectronic Device Platform in a Complementary Metal Oxide Semiconductor Technology

International audienceWe report a patterning strategy for building the first monoelectronic device complementary metal oxide semiconductor (CMOS)-compatible platform, including a single-electron transistor (SET) and multiple coupled quantum dots. Aggressive hybrid lithography (e-beam and deep UV are combined) and plasma etching are used to form adapted silicon active areas and gates, with a minimum size of 14 nm and a pitch of 80 nm after etching. These aggressive dimensions enable the study of double dots, a key structure for the more complex quantum circuits emerging now

Sensors and related devices for IoT, medicine and s mart-living

International audienceThe evolutions of medicine covering genome to exposome (i.e. all types of environmental exposures) [1] opened new paths of development for electronics including low power sensors. Additionally, the frontiers for new generations of sensors between smart-living, environment and health are fading. In this paper, we will give examples based on our developments in emerging autonomous sensors and medical devices, and show how they can be included in our daily lif