Wireless Biodevices and Systems

Conjunt de materials associats a l'assignatura Wireles Biodevices and System

Design, manufacture and characterization of compact filter assemblies for radiofrequency applications

This paper presents the use of additive manufacturing in the design and fabrication of a non-planar fully 3Dprinted low-pass filter. The process implements stereolithographic 3D printing and copper electroplating to produce the necessary parts and their casing. The filter we produce acts as a demonstrator: we present the possibility of constructing building blocks and combining different elements into a full assembly for system integration. We introduce the "drop-and-screw" concept, which is implemented to mount the parts into a single connectorized assembly without the need for welding. The method we propose may be suitable for building other components by simply changing the building blocks. We pay special attention to the design of the constituent parts of the filter (a 3D conical inductor and a 3D capacitor), exploring new geometries to reduce the size of the final filter prototypes. The results demonstrate the potential of additive manufacturing in the construction of high-performance RF components and assemblies, and we present a modular prototype with a high degree of reconfigurability and multifunctionality

Analysis and Optimization of Multi-Winding Toroidal Inductors for Use in Multilayered Technologies

The aim of this paper is to compare the performance of planar toroidal inductors and circular spiral inductors in multilayered technologies, in terms of achievable inductance density. New multi-winding toroidal inductor geometry is proposed to cover as much of the integration area as possible with the component footprint. The optimization of planar multi-winding toroidal inductors in multilayered substrates is investigated theoretically, and closed formulae are derived for their inductances as a function of geometrical parameters for any given value of the number of windings in the coil. The model obtained is validated experimentally and through electromagnetic simulation. Comparing the inductance of multi-winding toroidal inductors and compact spiral inductors allows us to update previously reported selection rules for the most suitable topology that leads to the most compact design

HERC 1 Ubiquitin Ligase Mutation Affects Neocortical, CA3 Hippocampal and Spinal Cord Projection Neurons: An Ultrastructural Study

The spontaneous mutation tambaleante is caused by the Gly483Glu substitution in the highly conserved N terminal RCC1-like domain of the HERC1 protein, which leads to the increase of mutated protein levels responsible for cerebellar Purkinje cell death by autophagy. Until now, Purkinje cells have been the only central nervous neurons reported as being targeted by the mutation, and their degeneration elicits an ataxic syndrome in adult mutant mice. However, the ultrastructural analysis performed here demonstrates that signs of autophagy, such as autophagosomes, lysosomes, and altered mitochondria, are present in neocortical pyramidal, CA3 hippocampal pyramidal, and spinal cord motor neurons. The main difference is that the reduction in the number of neurons affected in the tarnbaleante mutation in the neocortex, the hippocampus, and the spinal cord is not so evident as the dramatic loss of cerebellar Purkinje cells. Interestingly, signs of autophagy are absent in both interneurons and neuroglia cells. Affected neurons have in common that they are projection neurons which receive strong and varied synaptic inputs, and possess the highest degree of neuronal activity. Therefore, because the integrity of the ubiquitin-proteasome system is essential for protein degradation and hence, for normal protein turnover, it could be hypothesized that the deleterious effects of the misrouting of these pathways would depend directly on the neuronal activity

Assessment of 3D Printing Technologies for Millimeter Wave Reflectors

Three different 3D printing technologies: Stereolithography (SLA), Fused Deposition Modeling (FDM) and HP Multi Jet Fusion Technology (MJF) are compared to build a parabolic reflector operating at 100 GHz. Fabrication tolerance and surface roughness before and after metallization are accurately measured. The performance of the reflectors is measured in the near field and its performance is compared against an optical grade reflector. In this way the performance of the final product is thoroughly assesse

Wireless Biodevices and Systems - eHealth Platform Based on Arduino

Documentació associada a 3 sessions docents on es desenvolopa una plataforma eHealth basada en Arduino

Vortex motion channeling effects in Nb with mesoscopic arrays of Ni lines

Ordered arrays of submicrometric Ni lines have been fabricated in sputtered Nb films. Magnetotransport R(H) and (I, V) curves were measured close to the critical temperature using a cross-shape bridge that allows us to apply current in two directions: parallel or perpendicular to the lines. The experimental results show anisotropic vortex motion with clear channeling effects. In R(H) data, magnetic features appear but they are absent in the (I, V) curves

The HERC proteins and the nervous system

The HERC protein family is one of three subfamilies of Homologous to E6AP C-terminus (HECT) E3 ubiquitin ligases. Six HERC genes have been described in humans, two of which encode Large HERC proteins -HERC1 and HERC2- with molecular weights above 520 kDa that are constitutively expressed in the brain. There is a large body of evidence that mutations in these Large HERC genes produce clinical syndromes in which key neurodevelopmental events are altered, resulting in intellectual disability and other neurological disorders like epileptic seizures, dementia and/or signs of autism. In line with these consequences in humans, two mice carrying mutations in the Large HERC genes have been studied quite intensely: the tambaleante mutant for Herc1 and the Herc2+/530 mutant for Herc2. In both these mutant mice there are clear signs that autophagy is dysregulated, eliciting cerebellar Purkinje cell death and impairing motor control. The tambaleante mouse was the first of these mice to appear and is the best studied, in which the Herc1 mutation elicits: (i) delayed neural transmission in the peripheral nervous system; (ii) impaired learning, memory and motor control; and (iii) altered presynaptic membrane dynamics. In this review, we discuss the information currently available on HERC proteins in the nervous system and their biological activity, the dysregulation of which could explain certain neurodevelopmental syndromes and/or neurodegenerative diseases

Improvement of the quality factor of RF integrated inductors by layout optimization

A systematic method to improve the quality (Q) factor of RF integrated inductors is presented in this paper. The proposed method is based on the layout optimization to minimize the series resistance of the inductor coil, taking into account both ohmic losses, due to conduction currents, and magnetically induced losses, due to eddy currents. The technique is particularly useful when applied to inductors in which the fabrication process includes integration substrate removal. However, it is also applicable to inductors on low-loss substrates. The method optimizes the width of the metal strip for each turn of the inductor coil, leading to a variable strip-width layout. The optimization procedure has been successfully applied to the design of square spiral inductors in a silicon-based multichip-module technology, complemented with silicon micromachining postprocessing. The obtained experimental results corroborate the validity of the proposed method. A Q factor of about 17 have been obtained for a 35-nH inductor at 1.5 GHz, with Q values higher than 40 predicted for a 20-nH inductor working at 3.5 GHz. The latter is up to a 60% better than the best results for a single strip-width inductor working at the same frequency

Laser-induced forward transfer: a digital approach for printing devices on regular paper

Inkjet printing (IJP) is the most widespread direct-write technique in paper electronics. However, its use is limited, since its low-viscosity nano-inks leak through the cellulose fibers. Thus, a planarization coating is frequently used as barrier, despite that this makes substrates more expensive and less ecofriendly. Alternatively, high solid content screen printing (SP) inks could allow printing on regular paper due to their high viscosity and their large particle size; however, they cannot be printed through IJP. Another digital technique is required: laser-induced forward transfer (LIFT). The aim of this work is to prove the feasibility of LIFT for printing devices on regular paper. The main transfer parameters are systematically varied to obtain uniform Ag-SP interconnects, which performance is improved by a multiple-printing approach, resulting in low resistances with a much better performance than those typical of IJP. After optimizing the printed lines functionality, a proof-of-concept consisting on a radio-frequency inductor is provided. The characterization of the device shows a substantially higher performance than that of the same device printed with IJP ink in similar conditions, which proves the potential of LIFT for digitally fabricating devices on regular paper