Trottinette électrique ITROTT – circuit de recharge de batteries

Pour sa source d’énergie, la trottinette développée au LAI (iTrott) utilise un pack de 10 accumulateurs de type lithium-polymère (LiPo). La recharge de ces accumulateurs doit se faire de manière contrôlée et ceci pour chaque cellule élémentaire. Le projet proposé ici consiste à mettre en œuvre un circuit intégré de contrôle et à réaliser un PCB que l’on intégrera ultérieurement à la trottinette électrique

Synthesis of superposition shape images by light interacting with layers of lenslets

The present invention describes methods and apparatuses for creating superposition shape images by superposed base and revealing layers of lenslet gratings. The superposition shape images form a message recognizable by a human observer or by an image acquisition and computing device such as a smartphone. The superposition shape images may be created by different superposition techniques ranging from 1D moiré, 2D moiré and level-line moiré superposition techniques to lenticular image and phase shift superposition techniques. Moiré superposition techniques enable creating superposition shape images at different apparent depth levels. Applications comprise the protection of documents and valuable articles against counterfeits, the creation of eye-catching advertisements as well as the decoration of buildings and exhibitions

1D moiré shapes by superposed layers of micro-lenses

Two superposed layers of transparent cylindrical lenslet gratings create classical moiré fringes, when illuminated from behind. We rely on this observation to conceive special devices made of superposed lenslet gratings that produce animated moirés when they are tilted against the light. One-dimensional moirés can show a message moving back and forth along a given direction or radially expanding towards the exterior of a disk. These 1D moirés are conceived by fabricating two layers of micro-lenses on both sides of a transparent substrate. The top layer is a rectilinear grating of cylindrical lenslets and the bottom layer is an arrangement of smaller lenslets of different sizes and orientations that create a high contrast. Moirés created by superpositions of lenslets are visually striking and can be challenging to fabricate. Therefore they have a high potential for art, decoration, and document security

Level-line moirés by superposition of cylindrical microlens gratings

Two superposed layers of transparent cylindrical lenslet gratings create classical moiré fringes when illuminated from behind. We rely on this observation to conceive special devices made of superposed lenslet gratings that produce compelling beating shapes when tilted against the light. Level-line moirés are created by superposing gratings of cylindrical lenslets of the same period on both sides of a substrate and by locally shifting some of the cylindrical lenses according to the moiré theory. Depending on the illumination and the viewing conditions, constant light intensities or colors move across graphical elements or faces. Such level-line moiré samples have been fabricated and characterized to determine the optimal fabrication parameters. Thanks to their striking visual appeal and their relatively challenging fabrication, moirés created by superposition of lenslets have a high potential for document security, art, and decoration