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International audience; Bluetooth Low Energy (BLE) is a promising 2.4 GHz technology for Body Area Networks (BAN) in health care and lifestyle applications. However, the global increase of wireless devices using the crowded spectrum in the 2.4 GHz frequency band can create coexistence issues. This work studies the performance of BLE in environments with multiple BLE devices. An experimental setup consisting of 10 BLE nodes is used to measure BLE application throughput with different connection parameters and under different interference sources, such as other BLE devices and WiFi. The results quantify the decrease of the application throughput and the influence of BLE connection parameters in the experimental settings, as well as suggest parameter values suitable for densely deployed environments.

International audience; This paper reports the fabrication of arrays of vertical piezoelectric nanowires which are individually contacted at their base, and demonstrates that an electrical response to strain can be obtained from individual nanowires from the array, without external biasing exploiting the piezotronic effect. Such a technology could thus be used for the fabrication of self-powered sensors for mechanical strain mapping, where each individually contacted nanowire would act as the strain sensing equivalent of a pixel. Lateral mapping resolutions in the micrometer range can be obtained. Here, the hydrothermal method was used to grow vertical ZnO nanowires selectively between two electrodes that had been patterned beforehand. For the sake of demonstration, nanowires deflection was produced by subjecting the array of nanowires to an incident lateral gas flow of controlled rate, which was switched on and off repeatedly across the sample while electrical response was measured. Different experimental configurations were tested in terms of flow rate, flow orientation, or nanowire position with respect to tube outlet. Experiments were carried out with compressed nitrogen and air. The experimental results are fully consistent with the piezoelectric and piezotronic response which can be expected with this geometry. Moreover, it is shown that the electrical response under nitrogen flow is a linear function of flow rate and that its sign provides information about flow direction. These results demonstrate the very promising prospects of this new technology for high-resolution mapping, with potential applications in gas or liquid flow sensing, fingerprints detection or human-machine interfaces.

International audience; The 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 life