Hybrid integration of III/V lasers on a silicon-on-insulator (SOI) optical board

Abstract: Heterogeneous integration of III-V semiconductor materials on a silicon-on-insulator (SOI) platform has recently emerged as one of the most promising methods for the fabrication of active photonic devices in silicon photonics. For this integration, it is essential to have a reliable and robust bonding procedure, which also provides a uniform and ultra-thin bonding layer for an effective optical coupling between III-V active layers and SOI waveguides. A new process for bonding of III-V dies to processed siliconon-insulator waveguide circuits using divinylsiloxane-bis-benzocyclobutene (DVS-BCB) was developed using a commercial wafer bonder. This "cold bonding" method significantly simplifies the bonding preparation for machine-based bonding both for die and wafer-scale bonding. High-quality bonding, with ultra-thin bonding layers (<50 nm) is demonstrated, which is suitable for the fabrication of heterogeneously integrated photonic devices, specifically hybrid III-V/Si lasers. K. Mayora, "Novel three-dimensional embedded SU-8 microchannels fabricated using a low temperature full wafer adhesive bonding," J. Micromech. Microeng. 14(7), 1047-1056 (200

Pneumoconiosis and respiratory problems in dental laboratory technicians: Analysis of 893 dental technicians

Objectives: To explore the rate of pneumoconiosis in dental technicians (DTP) and to evaluate the risk factors. Material and Methods: Data of 893 dental technicians, who were admitted to our hospital in the period January 2007–May 2012, from 170 dental laboratories were retrospectively examined. Demographic data, respiratory symptoms, smoking status, work duration, working fields, exposure to sandblasting, physical examination findings, chest radiographs, pulmonary function tests and high-resolution computed tomography results were evaluated. Results: Dental technicians’ pneumoconiosis rate was 10.1% among 893 cases. The disease was more common among males and in those exposed to sandblasting who had 77-fold higher risk of DTP. The highest profusion subcategory was 3/+ (according to the International Labour Organization (ILO) 2011 standards) and the large opacity rate was 13.3%. Conclusions: To the best of our knowledge, it was the largest DTP case series (N = 893/90) in the literature in English. Health screenings should be performed regularly for the early diagnosis of pneumoconiosis, which is an important occupational disease for dental technicians

Badanie przewodności elektrycznej i charakterystyka czułości na wilgotność ceramiki BaTiO₃ z dodatkiem PMMA

Humidity sensing is a requirement for human comfort and several industrial processes. There are two main types of humidity-sensing mechanisms. One of them is the protonic sensor which utilizes ionic conductivity due to water physisorption or capillary condensation in micropores. The semiconductor sensors use the changes in electronic conductivity due to water chemisorption. In this study, an ionic type of sensor was fabricated. Barium titanate based ceramic humidity sensors made with PMMA(Polymethyl metacrylate) as the PFA (Pore-forming agent) were investigated. All compositions included 0.18 wt. % of La2O3 and three different PMMA contents. The green compacts were heated at 1200-1500 º C for 2-6 h. in air and then furnace cooled. The fundamental characteristics of ceramic humidity sensors, electrical conductivity and humidity sensitivity were determined and discussed in relation to microstructural features, porosity, phase analysis and grain size data. The experimental results of conductivity measurements were evaluated in terms of practical sensor applications.Pomiar wilgotności jest istotny dla ludzkiej wygody i wielu procesów przemysłowych. Istnieją dwa główne typy mechanizmów wykrywania wilgoci. Jednym z nich jest czujnik protonic, który wykorzystuje przewodnictwo jonowe dzięki fizyko sorpcji wody lub kondensacji kapilarnej w mikroporach. Czujniki półprzewodnikowe wykorzystują zmiany przewodnictwa elektrycznego ze względu na chemisorpcje wody. W ramach niniejszej pracy, zbudowany został czujnik jonowy. Badane były ceramiczne czujniki wilgotności oparte o tytanian baru z dodatkiem PMMA (polimetakrylan metakrylanu) jako czynnika tworzenia porów. Wszystkie badane składy zawierały 0,18%.wag La2O3 i trzy różne zawartości PMMA. Zielone pakiety ogrzewano w temperaturze 1200-1500 º C przez 2-6 godzin w powietrzu, a następnie studzono razem z piecem. Podstawowe cechy ceramicznych czujników wilgotności, przewodność elektryczną i wrażliwość na wilgotność zostały określone i omówione w odniesieniu do cech mikrostruktury, porowatości, analizy fazowej i danych o wielkości ziarna. Eksperymentalne wyniki pomiarów przewodności były oceniane w kategoriach praktycznych zastosowań czujników