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This work presents a flexible polyimide-based capacitive tactile sensing array with sub-millimeter spatial resolution. The sensor is conceived to be embedded in a multimodal artificial finger to detect and classify the texture morphology of an object's surface. The proposed tactile sensor comprises a 16 × 16 array of capacitive sensing units. Each unit is composed of a parallel square electrode pairs (340 µm × 340 µm) separated by a compressible air cavity and embedded into a flexible polyimide substrate. Standard MEMS microfabrication techniques were used to develop the sensor. The polyimide device was covered with a thin compressible PDMS layer to tune the normal pressure sensitivity and dynamic range (225-430 µm thin PDMS layer resulting in 0.23-0.14 fF/kPa). The detection of the surface morphologies of a regular grating stamp for different orientation and a small metallic nut placed on the sensor is demonstrated, showing a 420 µm spatial resolution. The proposed sensor represents a novel capacitive tactile sensing device with a sub-mm resolution of human fingertip sensitivity. [2020-0188]

It is well known that neural activity can be modulated using a cooling device. The applications of this technique range from the treatment of medication-resistant cerebral diseases to brain functional mapping. Despite the potential benefits of such technique, its use has been limited due to the lack of suitable thermal modulators. This paper presents the design and validation of a solid-state cooler that was able to modulate the neural activity of rodents without the use of large and unpractical water pipes. A miniaturized thermal control solution based exclusively on solid-state devices was designed, occupying only 5 mm × 5 mm × 3 mm, and featuring the potential for wireless power and communications. The cold side of the device was cooled to 26 °C, while the hot side was kept below 43 °C. This range of temperatures is compatible with brain cooling and efficient enough for achieving some control of neural activity.

Wireless power transfer using coupling in the near-field, in opposition to far-field, shows advantages concerning link efficiency, however the link performance is widely dependent on proper antenna positioning. The transmission of energy using a far-field link would be desirable in many applications, namely for powering biomedical devices placed inside the body. This paper presents results from a system that was designed to operate inside the human body and relies on a 3D antenna (500x500x500 µm 3 ), fabricated using self-folding technology, operating in the low gigahertz range. Wireless power transmission and power conversion between 1 and 4 GHz were evaluated. Far-field wireless power transmission was demonstrated using the electrically small microantenna and a DC load of 1 kΩ.

An implantable focal cooling device based on aPeltier is proposed in this paper. The building blocks of this device, namely its battery management, wireless power transfer, communication, and power management modules are presented and discussed. Simulated and experimental data in a deionized water phantom at 37 o C validate the use of the Peltier as a focal cooling device, and simulations in rat brain further confirm this conclusion.

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Les matériaux d'addition font actueÌlement pâÌtie des développements les plus récents dans la production du bétoÌr, caÌ Ì'üÍilisation des additions apporte uno amélioration des proprìáés mécâniques et de Ìa durabilité dü béton. D'autre part, leur utilisation a pour objectif de réduire la consommation de ciment. en conlribuant de maniere simple et économique à résoudre les problèmes liés à l'environnenent. Cet aÌlicle étudie les avantâges et Ìes limitations de la substin-rtion pafiielle du ciment par le nétakaolin. Les résultats obtgnus démontrent que cette substituüon apporte, pouÌ Ìe béton de même ordre dc résistancc à ìa compression, une amélioration considérable au niveau de Ìa durabilité. Ce qui penÌet de conclwe quc lc métakaolin est un substitut efficace câpable de rédui.e le contenu de ciment pour l'obtention de bétons équivalents. 1359-5997 O 2004 zuLEM. AÌl Íights rese.ved.