Multimodal transistors as ReLU activation functions in physical neural network classifiers

Artificial neural networks (ANNs) providing sophisticated, power-efficient classification are finding their way into thin-film electronics. Thin-film technologies require robust, layout-efficient devices with facile manufacturability. Here, we show how the multimodal transistor’s (MMT’s) transfer characteristic, with linear dependence in saturation, replicates the rectified linear unit (ReLU) activation function of convolutional ANNs (CNNs). Using MATLAB, we evaluate CNN performance using systematically distorted ReLU functions, then substitute measured and simulated MMT transfer characteristics as proxies for ReLU. High classification accuracy is maintained, despite large variations in geometrical and electrical parameters, as CNNs use the same activation functions for training and classification

Ultra-compact multi-level digital-to-analog converter based on linear multimodal thin-film transistors

International audienceA new device, the Multimodal Transistor (MMT), separates charge injection from conduction and achieves a linear dependence of drain current on its control gate voltage. This functionality is used to implement a highly compact digital-to-analog-converter, capable of performing 3-level, 3-bit conversion with minimal error (1.2% of LSB). © 2020 SID

Engineering current-voltage linearity in TFTs for analog and neuromorphic computing

International audienceMany emerging analog and neuromorphic applications would benefit from a fully linear dependence of a transistor's output on its input for reduced distortion and facile design of linear functions. We show how a new TFT structure, the multimodal transistor, can achieve a linearly dependent drain current in saturation (constant transconductance) with direct proportionality over a large range of input voltages

The multimodal thin-film transistor (Mmt): A versatile low-power and high-gain device with inherent linear response

International audienceA new device, the Multimodal Transistor (MMT), separates charge injection from conduction. With design optimization, it can achieve a constant transconductance with independent on/off switching of output current. This functionality has ample applications in energy efficient analog computation and hardware learning. © 2020 SID

Millimeter-Wave and Sub-THz Modulated Metasurface Antennas

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Modulated metasurface antennas and arrays for millimeter wave and sub-terahertz applications

International audienceThis summary presents the application of modulated metasurfaces in millimeter wave and sub-terahertz antenna systems. We succinctly show that by adopting metasurfaces as array element, one may mitigate some of the challenges found in large phased arrays with a limited field of view and concurrently enhance the gain bandwidth of modulated metasurfaces antennas with a single port. © 2023, META Conference. All rights reserved

Tour d’horizon des possibilités du Silicium : de l’électronique aux dispositifs de récupération d’énergie et capteurs micro-usinés

Un jeu de masques est réalisé permettant aux étudiants de fabriquer un système intégré comportant différentes fonctions de détection et une électronique de traitement en utilisant une technologie silicium associée à de la microtechnologie. Le but est de faire prendre conscience aux étudiants de la très grande diversité d’applications que peut fournir un système intégré silicium

Investigation on icp-cvd as a polyvalent low cost technology dedicated to low temperature μ-si tft prototyping.

International audienceA Corial Inductively Coupled Plasma Chemical Vapor Deposition (ICP-CVD) system has been investigated to produce un-doped and doped μ-Si layers, as well as insulators, leading to a general capability of performing N and P type TFTs. This enables to develop rapid prototyping of TFTs. Resistivity of layers and TFT issues from ICP-CVD have been electrically characterized. © 2020 SID

Microcrystalline silicon: Strain gauge and sensor arrays on flexible substrate for the measurement of high deformations

International audienceThis paper presents strain sensor arrays on flexible substrates able to measure local deformation induced by radii of curvature of few millimeters. Sensors use n-type doped microcrystalline silicon (μc-Si) as piezoresistive material, directly deposited on polyimide sheets at 165 °C. Sensitivity of individual sensors was investigated under tensile and compressive bending at various radii of curvature, down to 5 mm. A Transmission Line Method was used to extract the resistivity for each radius. The devices exhibited longitudinal gauge factors of −31 and longitudinal piezoresistive coefficients of −4.10−10 Pa−1. Reliability was demonstrated with almost unchanged resistances after cycles of bending (standard deviation of 1.7%). Strain gauge arrays, composed of 800 resistors on a 2 cm2 area, were fabricated with a spatial resolution of 500 × 500 μm2. Strain mapping showed the possibility to detect local deformation on a single resistor or to detect larger objects. These strain sensor arrays can find applications when high sensitivity and high spatial resolution is required. This paper also showed that μc-Si can be a relevant semi-conductor candidate for flexible electronic