100 research outputs found
Coupling of Electro-active Polymers for Energy Harvesting Applications
No full textInternational audienceHarvesting human kinetic energy to produce electricity is an attractive alternative to batteries for applications in wearable electronic devices and smart clothing. Among the different technologies, electrostatic converters represent one of the most promising method for this application. This paper presents a soft electret-based energy harvesting device which exploits human body movement as energy source to produce electricity. The device consists on an electret polymer coupled with an elastomeric deformable membrane. The impact of the characteristics and properties of materials on the power output of the device was evaluated leading to the best choice for materials: Sylgard 186 as elastomeric membrane and Parylene C as electret. The experimental results of the performance of Parylene C as electret polymer are presented and discussed
New approach to improve the energy density of hybrid electret-dielectric elastomer generators
No full textSPIE Conference on Electroactive Polymer Actuators and Devices (EAPAD), Portland, OR, MAR 26-29, 2017International audienceHarvesting human kinetic energy to produce electricity is an attractive alternative to batteries for applications in wearable electronic devices and smart textile. Dielectric elastomers generators (DEGs) represent one of the most promising technologies for these applications. Nevertheless, one of the main disadvantages of these structures is the need of an external polarization source to perform the energetic cycle. In the present work, a hybrid electret-dielectric elastomer generator in DEG mode is presented. In this configuration, the electret material is used as polarization source of a classical DEG, i.e. an electrostatic generator based on electrical capacitance variation. The electrical energy output in this mode (1.06mJ.g(-1)) could be higher than the one obtained using a classical electret mode (0.55mJ.g(-1)), i.e. charges recombination. In this paper, the operation principle of the hybrid generator will be fully described and the design rules for the realization of the prototype will be presented. The experimental data obtained from the prototype will be compared to the results of FEM simulations
CMOS Compatible Hydrogen Sensor Using Platinum Gate and ALD–Aluminum Oxide
No full textInternational audienceIn this study, a p-Si/ALD-Al2O3/Ti/Pt MOS (metal oxide semiconductor) device has been fabricated and used as a hydrogen sensor. The use of such a stack enables a reliable, industry-compatible CMOS fabrication process. ALD-Al2O3 has been chosen as it can be integrated into the back end of the line (BEOL) or in CMOS, post processing. The device response and recovery are demonstrated with good correlation between the capacitance variation and the hydrogen concentration. Detection down to 20 ppm at 140 °C was obtained and a response time of 56 s for 500 ppm was recorded
Optimization of an electret-based soft hybrid generator for human body applications
No full textWOS:000484113600003International audienc
Contribution to the design of soft hybrid generators: combination of electroactive polymers
No full textInternational audienc
HCl Selective Etching of SiGe versus Si in Stacks Grown on (110)
No full textWe have investigated the lateral HCl selective etching of SiGe versus Si in various patterned (110) SiGe/Si stacks. Given that Si(110) vertical etch rates are roughly 4 times higher than Si(100) ones, a moderate HCl partial pressure (0.4 Torr) was adopted for this 600-700C study. A definite SiGe versus Si etch selectivity has been demonstrated on (110) for 30-40% of Ge (none for 20% of Ge). SiGe lateral etch rates higher in the [1-10] than in the [001] direction have also been evidenced. A definite increase of both [1-10] and [001] lateral etch rates occurred when increasing the Ge content, the SiGe layer thickness and the etch temperature. Mean selectivities for 15 nm thick layers were however not that high, 20 for Si0.7Ge0.3 and 60 for Si0.6Ge0.4. [1-10] versus [001] etch anisotropy was otherwise minimized for low temperature etches, high Ge content and thick SiGe layers.</jats:p
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