Abstract
Biofouling is the major factor that limits long-term monitoring studies with automated optical instruments. Protection of the sensing areas, surfaces, and structural housing of the sensors must be considered to deliver reliable data without the need for cleaning or maintenance. In this work, we present the design and field validation of different techniques for biofouling protection based on different housing materials, biocides, and transparent coatings. Six optical turbidity probes were built using polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), PLA with copper filament, ABS coated with PDMS, ABS coated with epoxy and ABS assembled with a system for in situ chlorine production. The probes were deployed in the sea for 48 days and their anti-biofouling efficiency was evaluated using the results of the field experiment, visual inspections, and calibration signal loss after the tests. The PLA and ABS were used as samplers without fouling protection. The probe with chlorine production outperformed the other techniques, providing reliable data during the in situ experiment. The copper probe had lower performance but still retarded the biological growth. The techniques based on transparent coatings, epoxy, and PDMS did not prevent biofilm formation and suffered mostly from micro-biofouling.

Abstract
This paper presents the results of a series of experiments aiming at the optimisation of vital sign monitoring using textile electrodes to be used in a swimsuit The swimsuit will integrate sensors for the measurement of several physiological and biomechanical signals, this paper will focus on ECG and respiratory movement analysis The data obtained is mainly intended to provide tools for evaluation of high-performance swimmers, although applications can be derived for leisure sports and other situations A comparison between electrodes based on different materials and structures, behaviour in dry and wet environments, as well as the behaviour in different extension states, will be presented The influence of movement on the signal quality, both by the muscular electrical signals as well as by the displacement of the electrodes, will be discussed The final objective is the integration of the electrodes in the swimsuit by knitting them directly in the suit's fabric in a seamless knitting machine

Abstract
This article describes a complete system prototype to be used in aesthetic mesotherapy. The system is composed by two main blocks: a Master block, whose chief component is a CPU, which provides the user interface and a Slave block, implemented with a micro controller and a wave generator, which produces the appropriated voltages and currents compatible with the mesotherapy treatments. The whole system is powered by a 12V power supply and the output signal has a voltage that range between -54 V and 54 V. The output signal is composed by the overlap of two frequencies: the first one is selected in the range from 1.2 kHz to 1.8 kHz and the second one is in the range from 0.07 Hz to 2 Hz. The system is being tested in clinical environment with real patients showing very good promising results.

Abstract
This article describe the design, fabrication steps and experimental results of a dilatometer that will be used to characterize ceramic samples in terms of thermal expansion. The basic idea is to heat a 25 mm ceramic sample up to 1000 degrees C and register its dimension variations during the rising and the falling of the temperature. The device prototype consists in a master-slave structure since there are two control units: the high-level one (master) and a low-level one (slave). The high-level control unit will be responsible for supporting the user interface, exchanging and processing the necessary information between the user and the low-level control unit. The low-level control unit main component is a microcontroller. It is responsible for acquiring data from the strain and temperature sensors and controlling the temperature of the samples. The experimental results show that the prototype is appropriate for dilatometry essays once the maximum error was 0.037% of full-scale.

Abstract
This article describes the concept, design, fabrication and experimental results of a touchscreen based on acoustic pulse recognition. It uses piezoelectric transducers fabricated from the piezoelectric polymer poly(vinylidene fluoride), PVDF, in its beta phase. The transducers are located at the edges of the panel in order to receive the acoustic pulses generated by the touches. Each transducer is connected to a readout electronic circuit composed by a differential charge amplifier and a comparator, whose output signal is attached to a microcontroller. The microcontroller uses an algorithm to determine the location of the touch, based on the time differences of the transducer signals. The touchscreen itself is made of ordinary glass, providing good durability and optical transparency. The experimental results obtained with the first prototype demonstrate the effectiveness of the method.

Abstract
Despite huge advances in wireless communications in the last few years, underwater wireless communications is still a not fully developed technology, due to the lack of efficiency of radio waves for underwater communication. This problem can be overcome by using acoustic waves instead. In order to implement high-speed acoustic communications, it is imperative to develop transducers with high performance at high frequency. In this paper, a study of both piezoelectric ceramics and polymers used as water-coupled ultrasonic transducers is presented. As the main goal is to analyze their performance for high-speed communications, the behaviour of the piezoelectric ceramic (lead zirconate titanate, PZT) and the piezoelectric polymer (poly(vynilidene fluoride), PVDF) at high frequencies in underwater environment are compared. Results show that PVDF has a better response under the same ideal conditions, mainly with increasing frequency. (C) 2010 Published by Elsevier Ltd.