Ultrasensitive interferometric on-chip microscopy of transparent objects

Light microscopes can detect objects through several physical processes, such as scattering, absorption, and reflection. In transparent objects, these mechanisms are often too weak, and interference effects are more suitable to observe the tiny refractive index variations that produce phase shifts. We propose an on-chip microscope design that exploits birefringence in an unconventional geometry. It makes use of two sheared and quasi-overlapped illuminating beams experiencing relative phase shifts when going through the object, and a complementary metal-oxide-semiconductor image sensor array to record the resulting interference pattern. Unlike conventional microscopes, the beams are unfocused, leading to a very large field of view (20 mm(2)) and detection volume (more than 0.5 cm(3)), at the expense of lateral resolution. The high axial sensitivity (<1 nm) achieved using a novel phase-shifting interferometric operation makes the proposed device ideal for examining transparent substrates and reading microarrays of biomarkers. This is demonstrated by detecting nanometer-thick surface modulations on glass and single and double protein layers.Peer ReviewedPostprint (published version

Definición de una microrred para la recarga de vehículos eléctricos

ISBN 978-84-933682-3-4National audienceEn este estudio se plantea una amplia descripción de los centros de recarga para vehículos eléctricos, sus elementos constituyentes, su conjunción con las energías renovables y la variedad de escenarios que pudieran surgir a partir de su desarrollo y paulatina implantación

Ultrasensitive interferometric on-chip microscopy of transparent objects

Light microscopes can detect objects through several physical processes, such as scattering, absorption, and reflection. In transparent objects, these mechanisms are often too weak, and interference effects are more suitable to observe the tiny refractive index variations that produce phase shifts. We propose an on-chip microscope design that exploits birefringence in an unconventional geometry. It makes use of two sheared and quasi-overlapped illuminating beams experiencing relative phase shifts when going through the object, and a complementary metal-oxide-semiconductor image sensor array to record the resulting interference pattern. Unlike conventional microscopes, the beams are unfocused, leading to a very large field of view (20 mm(2)) and detection volume (more than 0.5 cm(3)), at the expense of lateral resolution. The high axial sensitivity (<1 nm) achieved using a novel phase-shifting interferometric operation makes the proposed device ideal for examining transparent substrates and reading microarrays of biomarkers. This is demonstrated by detecting nanometer-thick surface modulations on glass and single and double protein layers.Peer Reviewe

Remotely monitoring offshore wind turbines via ZigBee networks embedded with an advanced routing strategy

As better wind speeds are available offshore compared to on land, offshore wind power contribution in terms of electricity supplied is higher, thus more and more offshore wind turbines have been and will be deployed. However, the severe offshore conditions make it necessary to develop reliable and cost-effective real-time monitoring system when building offshore wind power farms. This paper proposes an innovative method for designing remote monitoring system for offshore wind turbines based on ZigBee wireless sensor networks. ZigBee networks carrying variety of sensors actively collect dynamic data related to the system operation status, including parameters of the mechanical unit and electrical unit as well as the operation environment. Each wind turbine itself represents a single wireless network, which sends information to remote monitoring center by GPRS module to achieve full wireless communication. To enhance the topologic efficiency and reduce the energy consumption of the networks, an optimized routing algorithm is developed. A physical system based on such method is developed. Analysis and experiment tests with real wind farm data indicate that the developed system works fairly well. The fundamental idea as studied in this work is of great value for building reliable and affordable real-time monitoring systems for wind farms (offshore and on land) with enhanced safety and efficiency

Multi-agent systems for the dependability and safety of microgrids

International audienceThe electrical networks are very complex systems, presently in full evolution. With the increasing penetration and apportionment over large areas of the renewable energies, the centralized nature of the power production evolves toward a more distributed form. In this context, the interest of the microgrids, as subcomponents of the main grid, rises especially by the specific services that they can provide. To ensure the stability and the dependability of a microgrid is a difficult task particularly in islanded mode. The microgrid is a mix of different types of elements and its structure may evolve. The multi-agents systems technique, with its distributed and adaptive character, can be an interesting tool for the control of each microgrid component and for the real time decision making related to the microgrid management. The paper starts with a presentation of microgrids and their specific issues, and follows with some basic concepts on multi-agents systems. Then, a review of the proposed techniques and algorithms that implies multi-agents systems in microgrids management is presented, focusing on the safety and the dependability in microgrids