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For some industrial applications, an accurate estimation of a light source position is needed. That is the case for a heliostat, a device that projects sunlight onto a focus hundreds of meters away from its aiming point. In this paper, we present a novel sensor design for generating an alignment error signal. Included is a detailed study of its response, which shows that certain geometrical design parameters are necessary to achieve desired accuracy. This sensor has been implemented using microelectromechanical system techniques to achieve a robust structure at low cost and it has been successfully applied to sun-tracking systems. Experimental results obtained in field tests are included. Index Terms--Microelectromechanical system (MEMS), microsensors, power generation, solar energy, sun-tracking control.

Use of advanced communication technologies, highly integrated control, and programming platforms drastically increases the performance of industrial control systems. That is the case of Motronic, where the synergistic collaboration between industry and academia has led to an advanced distributed network control system. To be commercially successful, it needs to have a low cost and to be robust, even if this requirement implies that it is a custom design and not based on previously existing commercial solutions. Use of standards and off-the-shelf products lower development costs, but usually raise production costs. In this paper, we show that, in certain applications, design of a new system from scratch is more advantageous. This system comprises a set of dynamically reconfigurable local controller nodes, a graphical programming environment, a remote supervision and control system, and a fault-tolerant fiber optical network. TCP/IP connectivity is provided by the use of a local gateway. Motronic is currently being applied in the integrated control of large production plants and in energy and power management industries. Index Terms--Cost analysis, distributed control, internetworking, real-time systems, supervisory control and data acquisition (SCADA) systems, token networks.

The field of industrial electronics has evolved profoundly during recent decades, hand in hand with smart systems, enabling the development of new functionalities. It is now common for robots to perform many previously burdensome tasks and operate in collaboration with humans. Miniaturized sensors, which are capable of extracting industrial process data with high levels of accuracy and robustness, are fully integrated to increment efficiency. Motion control systems have enabled the adaptation of systems to harsh industrial conditions, and all data related to sensing, operation, and control are interconnected using communication networks. Fault diagnosis strategies provide feasible control actions when abnormalities are detected. These are just a few examples that illustrate a revolution that has enabled the incorporation of smart systems into industrial processes. This article discusses how the incorporation of these capabilities has been made possible, and it examines the future challenges to further advances. [ABSTRACT FROM AUTHOR]

A depressurisation method to build SU-8 chambers as pneumatic energy reservoirs is described. The method consists in a combination of injection/extraction of uncrosslinked SU-8 and its exposure in different steps, intended to set the pressure of a chamber below atmospheric. These chambers are intended to be integrated with an actuation system to perform the extraction of fluids from the outside to the inside of a microfluidic SU-8 lab-on-a-chip. This method improves the portability of the platform because external pumps used to impulse the fluids can be avoided. [ABSTRACT FROM AUTHOR]

In this paper, a highly integrable pressurized thermo-pneumatic microvalve for impulsion and handling of fluids in portable SU-8 microfluidic platforms is reported. The microvalve aims to overcome the dependence on external pressure sources for actuation in this kind of platforms by incorporating a pressurized chamber in the design. The microvalve consists of two modules. The first one is a pressurized SU-8 chamber which makes the microvalve portable and is used to store pneumatic energy, and the second one is a gold wire inserted in a thin SU-8 wall to make a thermo-pneumatic and single-use actuation. The gold wire heats the thin wall up, and the pneumatic energy stored in the chamber exerts pressure on the wall simultaneously. The wall breaks due to the combination of these effects, releasing the pressure stored in the chamber, and creating an unidirectional flow in an output channel. The microvalve has been fabricated and tested in the laboratory showing an activation time of 1 s and a required energy of 188 mJ, values which fit the theoretical model. The advantages of this microvalve as a microfluidic component lie in its independence of external pressure sources, its high integrability with electronics and microfluidics in the same substrate [printed circuit board(PCB)], and the low consumption with respect to other PCB/SU-8 microvalves. [ABSTRACT FROM AUTHOR]

Printed circuit board (PCB) technology is well known, reliable, and low-cost, and its application to biomedicine, which implies the integration of microfluidics and electronics, has led to Lab-on-PCB. However, the biocompatibility of the involved materials has to be examined if they are in contact with biological elements. In this paper, the solder mask (PSR-2000 CD02G/CA-25 CD01, Taiyo Ink (Suzhou) Co., Ltd., Suzhou, China) of a commercial PCB has been studied for retinal cultures. For this purpose, retinal explants have been cultured over this substrate, both on open and closed systems, with successful results. Cell viability data shows that the solder mask has no cytotoxic effect on the culture allowing the application of PCB as the substrate of customized microelectrode arrays (MEAs). Finally, a comparative study of the biocompatibility of the 3D printer Uniz zSG amber resin has also been carried out. [ABSTRACT FROM AUTHOR]

Although prostate cancer is one of the most common cancers in the male population, its basic biological function at a cellular level remains to be fully understood. This lack of in depth understanding of its physiology significantly hinders the development of new, targeted and more effective treatment strategies. Whilst electrophysiological studies can provide in depth analysis, the possibility of recording electrical activity in large populations of non-neuronal cells remains a significant challenge, even harder to address in the picoAmpere-range, which is typical of cellular level electrical activities. In this paper, we present the measurement and characterization of electrical activity of populations of prostate cancer cells PC-3, demonstrating for the first time a meaningful electrical pattern. The low noise system used comprises a multi-electrode array (MEA) with circular gold electrodes on silicon oxide substrates. The extracellular capacitive currents present two standard patterns: an asynchronous sporadic pattern and a synchronous quasi-periodic biphasic spike pattern. An amplitude of ±150 pA, a width between 50–300 ms and an inter-spike interval around 0.5 Hz characterize the quasi-periodic spikes. Our experiments using treatment of cells with Gd3⁺, known as an inhibitor for the Ca2⁺ exchanges, suggest that the quasi-periodic signals originate from Ca2⁺ channels. After adding the Gd3⁺ to a population of living PC-3 cells, their electrical activity considerably decreased; once the culture was washed, thus eliminating the Gd3⁺ containing medium and addition of fresh cellular growth medium, the PC-3 cells recovered their normal electrical activity. Cellular viability plots have been carried out, demonstrating that the PC-3 cells remain viable after the use of Gd3⁺, on the timescale of this experiment. Hence, this experimental work suggests that Ca2⁺ is significantly affecting the electrophysiological communication pattern among PC-3 cell populations. Our measuring platform opens up new avenues for real time and highly sensitive investigations of prostate cancer signalling pathways. [ABSTRACT FROM AUTHOR]

Highlights • An autonomous culture system for electrostimulate organotypic cultures is presented. • The integration of microfluidic platforms together with sensors and actuators parts has been carried out successfully. • A protective effect on photoreceptor cell death in RP mouse retinal explants has been achieved. Abstract In this paper an autonomous culture system with the capability to electrostimulate organotypic cultures is described, and its utility is demonstrated by the neuroprotection achieved in retinal explants. The system is composed of a lab-on-chip (LOC), an electronic circuit and a data acquisition device. The LOC, in which the culture takes place, includes a microelectrode array (MEA), consisting of a PCB with a group of gold microelectrodes embedded in polydimethylsiloxane (PDMS), a microheater, a thermistor and a microfluidic circuit made of thermoplastic for feeding with culture medium. A plug made of PDMS has been included to facilitate the assembly of the culture LOC, the placement of the mouse retinas inside the MEA and the flow of culture medium. The transparency of the PDMS permits optical applications and a real time monitoring. An electronic circuit allows for a close monitoring of the experiment using a LabVIEW software specifically developed for this setting, including temperature control, heating and electrostimulation. In the experimental conditions, the retinal explants from retinitis pigmentosa mouse-models are dissected the day before neurodegeneration starts, when photoreceptor cell death is expected to progress along the following days, and cultured inside the LOC, using a fluorophore as a live-dead marker. The stimulation is a biphasic square signal of 0.5 V pp and it is applied for five minutes every other day. Unstimulated RP explants and healthy retinas are used as controls. After seven days, a histological study is performed. We have demonstrated the applicability of this system as an organotypic culture LOC to test the effect of electrostimulation in retinal explants from different mouse models, and found a protective effect on photoreceptor cell death in the conditions tested. [ABSTRACT FROM AUTHOR]