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Endoscopic endonasal approaches to pediatric skull base lesions are rare, challenging, and present distinct considerations from adult pathology. In this study, we describe our endoscopic technical approach to various skull base lesions demonstrating the efficacy and nuances of these approaches in pediatric patients.Pediatric patients underwent endoscopic approach for skull base lesions from January of 2015 to April of 2021 were included in the study. Presenting symptoms, indications for surgery, surgical outcomes, intraoperative and postoperative complications, length of hospital stay, and length of follow-up were documented.A total of 18 patients (median age 12, age-range 1-15, 53% male) underwent 19 endoscopic transsphenoidal procedures. The pathologies included craniopharyngioma (N = 5), biopsy for an unknown disease (n = 2; orbital meningioma and pituitary lymphocytic hypophysitis), pituitary adenoma (N = 2; ACTH-secreting and non-functional), Rathke's cleft cyst (n = 2), CSF leak repairs (n = 2; post-traumatic and spontaneous meningocele), juvenile nasopharyngeal angiofibroma (n = 3, 1 patient had 2 procedures) and rhabdomyosarcoma (n = 1). GTR was achieved in 11 out of 15 procedures (73.3%). Out of 10 patients with a sellar lesion, 6 patients had intraoperative CSF leak (60%). No patients experienced post-operative CSF leak. The median follow-up for all patients was 14 months (1-36 months).Anterior and middle skull base pathology in pediatric patients can be effectively operated via an endoscopic approach across a wide variety of patient ages and conditions. Minimally invasive techniques with middle turbinate and nasal septum preservation can be achieved without compromising outcomes. A wide variety of surgical repair strategies can be successfully utilized.

The UK Smart X-Ray Optics (SXO) programme is developing active/adaptive optics for terrestrial applications. One of the technologies proposed is microstructured optical arrays (MOAs), which focus X-rays using grazing incidence reflection through consecutive aligned arrays of microscopic channels. Although such arrays are similar in concept to polycapillary and microchannel plate optics, they can be bent and adjusted using piezoelectric actuators providing control over the focusing and inherent aberrations. Custom configurations can be designed, using ray tracing and finite element analysis, for applications from sub-keV to several-keV X-rays, and the channels of appropriate aspect ratios can be made using deep silicon etching. An exemplar application will be in the microprobing of biological cells and tissue samples using Ti Kα radiation (4.5 keV) in studies related to radiation-induced cancers. This paper discusses the optical design, modelling, and manufacture of such optics.

A silicon swimming robot or pond skating device has been demonstrated. It floats on liquid surfaces using surface tension and is capable of movement using electrowetting on dielectric (EWOD) based propulsion. Its dimensions are 6 × 9 mm and the driving mechanism involves first trapping air bubbles within the liquid onto the hydrophobic surface of the device. The air bubbles are then moved using EWOD, which provides the propulsion. The device employs a recently reported View the MathML source EWOD technology enabling a driving voltage of ≈15 V, which is low enough for RF power transmission, thus facilitating wire-free movement. A wired version has been measured to move 1.35 mm in 168 ms (a speed of 8 mm s−1). This low voltage-EWOD (

Piezoelectric actuators are widely utilised in adaptive optics to enable mirrors having an actively controlled reflective surface for the purpose of the wavefront correction by reducing the effects of rapidly changing optical distortion. Two new prototype adaptive X-ray optical systems are under development with the aim of approaching the fundamental diffraction limit. One proposed technology is microstructured optical arrays (MOAs) involving two or four piezoelectric strips bonded to a silicon wafer to produce a micro-focused X-ray source for biological applications, and which uses grazing incidence reflection through consecutive aligned arrays of channels obtained using deep silicon etching. Another technology is large scale optics which uses a thin shell mirror bonded with 20–40 piezoelectric actuators for the next generation of X-ray telescopes with an aim to achieve a resolution greater than that currently available by Chandra (0.5"). PZT-based piezoelectric actuators are being developed in this programme according to the design and implementation of the proposed mirror and array structures. Viscous plastic processing is chosen for the preparation of the materials system, which is subsequently formed and shaped into the suitable configurations. Precise controls on the thickness, surface finish and the curvature are the key factors to delivering satisfactory actuators. Unimorph type piezoelectric actuators have been proposed for the applications and results are presented regarding the fabrication and characterisation of such piezo-actuators, as well as the related design concepts and comparison to modelling work.

This paper presents test structures designed for studying the relationship between the operating voltage and different electrode configurations and areas for coplanar electrowetting on dielectrics (EWOD) devices. New test structures have been designed and fabricated using anodic Ta2O5 dielectric and thin aFP (amorphous Fluoropolymer CYTOP from Asahi Glass Co., Ltd.). These test structures have been used to characterize the contact angle change, which is between 114deg and 81deg with an applied voltage of less than 20 V. This demonstrates that by modifying the coplanar architecture, the operating voltage can be reduced by a factor of two, compared to previously reported coplanar EWOD structures. Droplet manipulation on a coplanar EWOD system with this new design has been successfully demonstrated, with a driving voltage of 15 V.

This paper presents a robust anodic Ta2O5 dielectric as an alternative insulator for fabricating low-voltage electrowetting on dielectric (EWOD) systems. Previously reported low-voltage EWOD technologies require high-temperature processes ( > 435degC), which unlike this room temperature technology, are not compatible with standard copper and aluminum integrated circuit interconnect technology as well as polymer-based substrates. The anodized Ta2O5 forms a uniform pinhole free layer with a surface roughness (R a) of 0.6 nm. This robust film enables an ultrathin amorphous FluoroPolymer layer to be employed to reduce the EWOD driving voltage to 13 V. Both sub-20-nm Teflon-AF and CYTOP layers have been successfully coated on top of Ta2O5 with good adhesion. Applying voltages of 6-15 V significantly modified the contact angles of droplets in air on these samples (121deg to 81deg on Teflon-AF at 13 V and 114deg to 95deg on CYTOP at 6 V). Successful 14-V EWOD manipulation involving droplets being dispensed from a reservoir, their movement, followed by merging them together has been demonstrated using devices using a Teflon-AF + Ta2O5 dielectric.

This paper reports a CMOS compatible fabrication procedure that enables electrowetting-on-dielectric (EWOD) technology to be post-processed on foundry CMOS technology. With driving voltages less than 15 V it is believed to be the lowest reported driving voltage for any material system compatible with post-processing on completed integrated circuits wafers. The process architecture uses anodically grown tantalum pentoxide as a pinhole free high dielectric constant insulator with an overlying 16 nm layer of Teflon-AF®, which provides the hydrophobic surface for droplets manipulation. This stack provides a very robust dielectric, which maintains a sufficiently high capacitance per unit area for effective operation at a reduced voltage (15 V) which is more compatible with standard CMOS technology. The paper demonstrates that the sputtered tantalum layer used for the electrodes and the formation of the insulating dielectric can readily be integrated with both aluminium and copper interconnect used in foundry CMOS.

Optical fibre pressure sensors have potential performance advantages over electrical sensors in measuring rapid transients such as shock waves from explosive blasts. We report the development of micromachined optical fibre Fabry–Perot pressure sensors using a silicon dioxide or nitride diaphragm and detail the fabrication stages of the sensor body and diaphragm. The planar technology used is based on silicon deep etching and direct fusion bonding of silicon wafers. Test results for both types of diaphragm are presented. Sensors with rise times better than 3 µs, range 0.1 to 1 MPa and resolution ~500 Pa have been demonstrated in explosives trials. Despite the difference in the sign of stress for the two diaphragm types, both demonstrated excellent high-speed response to explosively generated air shocks.

This paper reports the latest design and the associated fabrication technology of the Mk II prototype infrared (IR) detector for the two 5120 pixel SCUBA-2 (submillimetre common user bolometer arry) instruments, which are to be mounted on the James Clerk Maxwell telescope (JCMT) in Hawaii. Progress is described on the design and the technology modules being developed for the new detector, which is based upon silicon micromachining. The two arrays of transition edge sensors (TES) are used to detect incoming radiation with wavelengths of 450 and 850 μ respectively and as the SCUBA-2 detector operates at about 100 mK, it consequently involves integration with low-temperature electronics and careful design of the associated interconnect. A key aspect of the connection between the TES detector and readout electronics is the use of indium flip-chip bumps, which become superconducting at cryogenic temperatures. The integration of nanoscale membranes and transition edge sensors together with microsystem technology enables SCUBA-2 to have of the order of 10 -17W (1 Hz bandwidth) sensitivity to incoming radiation.

Submillimeter common user bolometer array (SCUBA)-2 is a wide field sub-mm bolometer camera designed to replace the existing SCUBA instrument on the JCMT in Hawaii. It will be many hundreds of times faster in large area mapping than SCUBA and will also go deeper in a single frame. It will enable the many discoveries of SCUBA to be followed up with deep systematic surveys and help act as a pathfinder for the ALMA interferometer. The key technologies for making the arrays have been demonstrated and will be put together to fabricate the first prototype later this year (2003). The wide field nature of the SCUBA-2 bolometer camera, combined with the diffraction limit at sub-mm wavelengths, leads to physically large focal planes where the issues of stray light control, magnetic shielding, and electrical, thermal and mechanical connection must be carefully addressed in order to realise a successful instrument. We describe the solutions we have adopted for these problem areas.

We describe the techniques used to fabricate SCUBA-2, the first large-format, filled array of bolometers for sub-millimeter astronomy. With two monolithic arrays of ∼10,000 bolometers, SCUBA-2 is made possible by a unique combination of advanced technologies. The detectors are made from thermally bonded and thinned silicon wafers whose surface is ion-implanted to match the impedance of free space. SCUBA-2s pixels are suspended on a View the MathML source silicon nitride membrane with low tensile stress. Deep-etch micromachining to View the MathML source by the Bosch process isolates each pixel thermally. Proximity effect transition edge sensors formed from Mo/Cu bilayers (Nucl. Instr. and Meth. A, these proceedings) are the temperature sensing elements for the bolometers. To read out such a large number of pixels, SCUBA-2 uses a superconducting quantum interference device readout for time domain multiplexing (Nucl. Instr. and Meth. A, these proceedings). The detector wafer is flip-chip bonded to the multiplexer wafer by indium bumps which provide electrical and thermal connections. The technologies that make SCUBA-2 possible have applications for large-format arrays from the submillimeter through the X-ray spectral regions.

The design and fabrication is described of the prototype IR detector for the SCUBA-2 80×80 pixel array (Submillimetre Common User Bolometer Array), which is to be mounted on the James Clerk Maxwell Telescope in Hawaii. The detector technology is based on silicon micromachining, with transition edge sensors (TES) being used to detect incoming radiation with wavelengths of 450 and 850 μm. Each TES is located on a λ/4 silicon brick suspended on a silicon nitride membrane and supported by a silicon micromachined waffle. Low-temperature indium bump bonding connects each TES to a SQUID multiplexer chip. The paper details the design considerations and the technology used to fabricate the detector wafer.

Prototype imaging subarrays for SCUBA-2 (the Submillimeter Common-User Bolometer Array) have been fabricated and tested. The pixel count (1280) of these wafer-scale imagers is significantly larger than any other low-temperature detectors produced to date, and represents a major step forward for the low-temperature detector community. These transition-edge-sensor (TES) based imagers utilize several innovations including in-focal-plane superconducting quantum intereference device (SQUID) multiplexers, micromachined Si block absorbers, and superconducting wafer hybridization. In this paper, we review the fabrication processes developed for these imagers and present recent optical data from a prototype imaging subarray.

SCUBA-2 is an innovative 10000 pixel bolometer camera operating at submillimetre wavelengths on the James Clerk Maxwell Telescope (JCMT). The camera has the capability to carry out wide-field surveys to unprecedented depths, addressing key questions relating to the origins of galaxies, stars and planets. With two imaging arrays working simultaneously in the atmospheric windows at 450 and 850 microns, the vast increase in pixel count means that SCUBA-2 maps the sky 100-150 times faster than the previous SCUBA instrument. In this paper we present an overview of the instrument, discuss the physical characteristics of the superconducting detector arrays, outline the observing modes and data acquisition, and present the early performance figures on the telescope. We also showcase the capabilities of the instrument via some early examples of the science SCUBA-2 has already undertaken. In February 2012, SCUBA-2 began a series of unique legacy surveys for the JCMT community. These surveys will take 2.5 years and the results are already providing complementary data to the shorter wavelength, shallower, larger-area surveys from Herschel. The SCUBA-2 surveys will also provide a wealth of information for further study with new facilities such as ALMA, and future telescopes such as CCAT and SPICA., 23 pages, 20 figures, 3 tables. Accepted by MNRAS

SCUBA-2 is a revolutionary 10,000 pixel wide-field submillimetre camera, recently commissioned and now operational at the James Clerk Maxwell Telescope (JCMT). Twin focal planes each consist of four 32 by 40 sub-arrays of superconducting Transition Edge Sensor (TES) bolometers, the largest combined low temperature bolometer arrays in operation, to provide simultaneous imaging at wavelengths of 450 and 850 microns. SCUBA-2 was designed to map large areas of sky more than 100 times faster than the original ground breaking SCUBA instrument and has achieved this goal. In this paper we describe the performance of the instrument and present results of characterising the eight science grade TES bolometer arrays. We discuss the steps taken to optimise the setup of the TES arrays to maximise mapping speed and show how critical changes to the sub-array module thermal design, the introduction of independent focal plane and 1K temperature control and enhancements to the cryogenics have combined to significantly improve the overall performance of the instrument.

The Smart X-Ray Optics (SXO) project comprises a UK-based consortium developing active/adaptive micro-structured optical arrays (MOAs). MOA devices are designed to focus X-rays using grazing incidence reflection through consecutive aligned arrays of microscopic channels. Adaptability is achieved using a combination of piezoelectric actuators, which bend the edges of the silicon chip, and a spider structure, which forms a series of levers connecting the edges of the chip with the active area at the centre, effectively amplifying the bend radius. The spider actuation concept, in combination with deep silicon etching stopped close to the surface, can also be used to create deformable mirrors where the curvature and tip/tilt angles of the mirror can be controlled. Finite Element Analysis (FEA) modelling, carried out for the optimization of the spider MOA device, indicates that deformable mirrors with curvature varying from flat to 5cm ROC and control over the tip/tilt angles of the mirror of +/-3mrad could be achieved. Test spider structures, manufactured using a Viscous Plastic Processing Process for the PZT piezoelectric actuators and a single wet etch step using planes in a (110) silicon wafer for both the silicon channels and the spider structure, have been bent to a radius of curvature smaller than 5 cm. This paper evaluates the spider MOA's concept as a means to achieve deformable mirrors with controllable ROC and control over the tip/tilt angles. FEA modelling results are compared with obtained characterization data of prototype structures. Finally, manufacturing and integration methods and design characteristics of the device, such its scalability, are also discussed.

This paper describes two fabrication techniques-dry and wet etching- for microstructured optical arrays (MOAs). The MOAs consist of arrays of channels deep etched in silicon. They use grazing incidence reflection to focus the X-rays through the consecutive aligned arrays of channels, ideally reflecting once off a vertical and smooth channel wall in each array. The MOAs were proposed by the Smart X-ray Optics (SXO) programme as small scale optics for micro-probing of biological cells and tissues. The first fabrication method requires inductively coupled plasma (ICP) using Bosch processes. The second one involves etching silicon wafers in alkaline solutions.

The Smart X-Ray Optics (SXO) project comprises a U.K.-based consortium developing active/adaptive micro-structured optical arrays (MOAs). These devices are designed to focus X-rays using grazing incidence reflection through consecutive aligned arrays of microscopic channels etched in silicon. Adaptability is achieved using a combination of piezoelectric actuators, which bend the edges of the silicon chip, and a spider structure, which forms a series of levers connecting the edges of the chip with the active area at the centre, effectively amplifying the bend radius. Test spider structures, have been bent to a radius of curvature smaller than 5 cm, indicating that in complete devices a suitable focal length using a tandem pair configuration could be achieved. Finite Element Analysis (FEA) modelling has been carried out for the optimization of the spider MOA device design. Prototype devices have been manufactured using a Viscous Plastic Processing technique for the PZT piezoelectric actuators, and a single wet etch step using {111} planes in a (110) silicon wafer for both the silicon channels and the spider structure. A surface roughness of 1.2 nm was achieved on the silicon channel walls. Characterisation techniques have been developed in order to evaluate the device performance in terms of the bending of the MOA channels produced by the actuators. This paper evaluates the progress to date on the development of spider MOA's comparing FEA modelling with the results obtained for prototype structures.

SCUBA-2 is a state of the art 10,000 pixel submillimeter camera installed and being commissioned at the James Clerk Maxwell Telescope (JCMT) providing wide-field simultaneous imaging at wavelengths of 450 and 850 microns. At each wavelength there are four 32 by 40 sub-arrays of superconducting Transition Edge Sensor (TES) bolometers, each packaged with inline SQUID multiplexed readout and amplifier. In this paper we present the results of characterising individual 1280 bolometer science grade sub-arrays, both in a dedicated 50mk dilution refrigerator test facility and in the instrument installed at the JCMT.

The Smart X-Ray Optics (SXO) project comprises a U.K.-based consortium developing active/adaptive micro-structured optical arrays (MOAs). These devices are designed to focus X-rays using grazing incidence reflection through consecutive aligned arrays of microscopic channels etched in silicon. The silicon channels have been produced both by dry and wet etching, the latter providing smoother channel walls. Adaptability is achieved using piezoelectric actuators, which bend the device and therefore change its focal distance. We aim to achieve a 5 cm radius of curvature which can provide a suitable focal length using a tandem pair MOA configuration. Finite Element Analysis (FEA) modelling has been carried out for the optimization of the MOA device design, consider different types of actuators (unimorph, bimorph and active fibre composites), and different Si/piezoelectric absolute and relative thicknesses. Prototype devices have been manufactured using a Viscous Plastic Processing Process for the piezoelectric actuators and dry etched silicon channels, bonded together using a low shrinkage adhesive. Characterisation techniques have been developed in order to evaluate the device performance in terms of the bending of the MOA channels produced by the actuators. This paper evaluates the progress to date on the actuation of the MOAs, comparing FEA modelling with the results obtained for different prototype structures.

Piezoelectric actuators are widely employed in adaptive optics to enable an actively controlled mirror surface and improve the optical resolution and sensitivity. Currently two new prototype adaptive X-ray optical systems are under development through the Smart X-ray Optics project in a UK based consortium. One proposed technology is micro-structured optical arrays (MOAs) which uses aligned micro-channels structures obtained by deep silicon etching using both dry and wet techniques and bonded piezoelectric actuators to produce a micro-focused X-ray source for biological applications. The other technology is large scale optics which uses a thin shell mirror segment with 20-40 bonded piezo-actuators for the next generation of X-ray telescopes with an aim to achieve a resolution greater than that currently available by Chandra (0.5"). The Functional Materials Group of Birmingham University has the capability of fabricating a wide range of piezo-actuators including, for example, unimorph, bimorph and active fibre composites (AFC) by using a viscous plastic processing technique. This offers flexibility in customising the shapes (from planar to 3-D helix) and feature sizes (>20 μm) of the actuators, as well as achieving good piezoelectric properties. PZT unimorph actuators are being developed in this programme according to the design and implementation of the proposed mirror and array structures. Precise controls on the dimension, thickness, surface finishing and the curvature have been achieved for delivering satisfactory actuators. Results are presented regarding the fabrication and characterisation of such piezo-actuators, as well as the progress on the large optic and MOAs prototypes employing the piezo-actuators.

The Smart X-ray Optics (SXO) programme is developing advanced active-adaptive optics for X-rays. There are two main themes: large optics for applications in astronomy and small scale optics for micro-probing of biological cells and tissue samples using Ti or Cr Kα radiation (4.5keV and 5.4keV, respectively) in studies related to radiation induced cancers. For the latter objective, microstructured optical arrays (MOAs) have been proposed. These consist of an array of channels deep etched in silicon. They use grazing incidence reflection to focus the X-rays through consecutive aligned arrays of channels, ideally reflecting once off a channel wall in each array. Bending the arrays allows variable focal length. The adaptivity is achieved by flexing the arrays using PZT (Lead Zirconate Titanate)-based piezo actuators. The array bending has been modelled using finite element analysis (FEA) and the results showed that for reasonable efficiency, the wall roughness of the channels should not exceed 2nm. This paper describes two techniques of fabrication the MOAs: dry etching and wet etching. The first method requires a special equipment called "inductively coupled plasma" (ICP) using Bosch processes that are designed to produce features with a high aspect ratio with vertical walls. The second method involves using an alkaline solution for etching silicon wafers. This type of wafer was selected because of the large wet etch ratio between the (111) and (100) planes that leads to smooth vertical walls. For our application tetra-methyl-ammonium hydroxide (TMAH) was used as it is fully compatible with CMOS integrated circuit processes.

This paper describes reflective adaptive/active optics for applications including studies of biological radiation damage. The optics work on the polycapillary principle, but use arrays of channels in thin silicon. For optimum performance the x-rays should reflect once off a channel wall in each of two successive arrays. This reduces aberrations since then the Abbe sine condition is approximately satisfied. Adaptivity is achieved by flexing the arrays via piezo actuation, providing further aberration reduction and controllable focal length. © 2009 IOP Publishing Ltd.

The UK Smart X-Ray Optics consortium is developing novel reflective adaptive/active x-ray optics for small-scale laboratory applications, including studies of radiation-induced damage to biological material. The optics work on the same principle as polycapillaries, using configured arrays of channels etched into thin silicon, such that each x-ray photon reflects at most once off a channel wall. Using two arrays in succession provides two reflections and thus the Abbe sine condition can be approximately satisfied, reducing aberrations. Adaptivity is achieved by flexing one or both arrays using piezo actuation, which can provide further reduction of aberrations as well as controllable focal lengths. Modelling of such arrays for used on an x-ray microprobe, based on a microfocus source with an emitting region approximately 1μm in diameter, shows that a focused flux approximately two orders of magnitude greater than possible with a zone plate of comparable focal length is possible, assuming that the channel wall roughness is less than about 2nm.

This paper presents test structures designed for studying the relationship between the operation voltage and the configuration of electrode area for coplanar EWOD (Electro Wet- ting On Dielectrics) devices. Robust anodic Ta2O5 dielectric and thin aFP (amorphous Fluoropolymer) have been used to fabricate the structures. Test structures have been used to characterise the significant contact angle change on asymmetric configurations, 114deg to 81deg on CYTOP (amorphous fluoropolymer from Asahi Glass Co. Ltd.) with an applied voltage of less than 20 V. This demonstrates that by modifying the design, the operating voltage can be reduced by a factor of two, compared to the existing symmetric coplanar EWOD structures. Droplet manipulation on a coplanar EWOD system with this new design has been successfully demonstrated, with a driving voltage of 15 V.

A silicon swimming robot or pond skating device has been demonstrated. It floats on liquid surfaces using surface tension and is capable of movement using electrowetting on dielectric (EWOD) based propulsion. Its dimensions are 6 times 9 mm with a thickness of 380 mum. The driving mechanism involves the trapping of air bubbles within the liquid onto the hydrophobic surface of the device with the subsequent ejection using a recently reported Ta2O5 EWOD technology. The required driving voltage of ~15 V is low enough for RF power transmission, thus providing wire-free movement. A wired version has been measured to move 1.35 mm in 168 ms (a speed of 8 mm s-1). This low-voltage EWOD device, fabricated using a CMOS compatible process, is believed to be the worldpsilas smallest swimming MEMS device that has no mechanical moving parts. The paper also reports results of EWOD droplet operation driven by wireless power transmission and demonstrates that such a wireless design can be successfully mounted on a floating EWOD device.

The UK Smart X-Ray Optics programme is developing the techniques required to both enhance the performance of existing X-ray systems, such as X-ray telescopes, while also extending the utility of X-ray optics to a broader class of scientific investigation. The approach requires the control of the inherent aberrations of X-ray systems using an active/adaptive method. One of the technologies proposed to achieve this is micro-structured optical arrays, which use grazing incidence reflection through consecutive aligned arrays of channels. Although such arrays are similar in concept to polycapillary and microchannel plate optics, they are more flexible. Bending the arrays allows variable focal length, while flexing parts of them provides adaptive or active systems. Custom configurations can be designed, using ray tracing and finite element analysis, for applications from sub-keV to several-keV X-rays. The channels may be made using deep silicon etching, which can provide appropriate aspect ratios, and flexed using piezo actuators. An exemplar application will be in the micro-probing of biological cells and tissue samples using Ti Kα radiation (4.5 keV) in studies related to radiation induced cancers.

SCUBA-2 is a submillimeter camera being built for the James Clerk Maxwell Telescope in Hawaii. Bringing CCD style imaging to the submillimeter for the first time, with over 10 000 pixels, it will provide a revolutionary improvement in sensitivity and mapping speed. We present results of the first tests on a prototype 1280 pixel SCUBA-2 subarray; the full instrument will be made up of eight such subarrays. The array is made up of transition edge sensor TES detectors, with Mo/Cu bilayers as the sensing element. To keep the number of wires reasonable, a multiplexed readout is used. Unlike previous TES arrays, an in-focal plane multiplexer configuration is used, in which the multiplexing elements are located beneath each pixel. To achieve the required performance, the detectors are operated at a temperature of approximately 120 mK. We describe the results of a basic electrical and optical characterization of the array, demonstrating that it is fully operational. Noise measurements were made on several pixels and gave a noise equivalent power below 2.5 10 17 WH Z 0.5 , within the requirements for SCUBA-2. The construction of the testbed used to carry out these measurements is also described. © 2007 American Institute of Physics. DOI: 10.1063/1.2436839

We describe the capabilities of SCUBA-2, the first CCD-like imager for submillimeter astronomy, and the technologies that make it possible. Unlike previous detectors using discrete bolometers, SCUBA-2 has two dc-coupled, monolithic arrays with a total of ~10,000 bolometers. SCUBA-2’s absorber-coupled pixels use superconducting transition edge sensors operating at ~ 120mK for photon-noise limited performance and a SQUID time-domain multiplexer for readout. It will offer simultaneous imaging of an 8 × 8 arcmin field of view at wavelengths of 850 μm and 450 μm. SCUBA-2 is expected to have a huge impact on the study of galaxy formation and evolution in the early Universe as well as star and planet formation in our own Galaxy. Mapping the sky to the same S/N up to 1000 times faster than SCUBA, SCUBA-2 will also act as a pathfinder for submillimeter interferometers such as ALMA. SCUBA-2 will begin operation on the JCMT in 2006.

SCUBA-2 is an innovative 10,000 pixel submillimeter camera due to be delivered to the James Clerk Maxwell Telescope in late 2006. The camera is expected to revolutionize submillimeter astronomy in terms of the ability to carry out wide-field surveys to unprecedented depths addressing key questions relating to the origins of galaxies, stars and planets. This paper presents an update on the project with particular emphasis on the laboratory commissioning of the instrument. The assembly and integration will be described as well as the measured thermal performance of the instrument. A summary of the performance results will be presented from the TES bolometer arrays, which come complete with in-focal plane SQUID amplifiers and multiplexed readouts, and are cooled to 100mK by a liquid cryogen-free dilution refrigerator. Considerable emphasis has also been placed on the operating modes of the instrument and the common-user aspect of the user interface and data reduction pipeline. These areas will also be described in the paper., 15 pages; in Proceedings of Millimeter and Submillimeter Detectors and Instrumentation, SPIE, in press

We present the results of characterization measurements on a 1280 pixel superconducting bolometer array designed for operation at wavelengths around 450 μm. The array is a prototype for the sub-arrays which will form the focal plane for the SCUBA-2 sub-mm camera, being built for the James Clerk Maxwell Telescope (JCMT) in Hawaii. With over 10 000 pixels in total, it will provide a huge improvement in both sensitivity and mapping speed over existing instruments. The array consists of molybdenum-copper bi-layer TES (transition edge sensor) pixels, bonded to a multiplexer. The detectors operate at a temperature of approximately 175 mK, and require a heat sink at a temperature of approximately 60 mK. In contrast to previous TES arrays, the multiplexing elements are located beneath each pixel (an "in-focal plane" configuration). We present the results of electrical and optical measurements, and show that the optical NEP (noise equivalent power) is less than 1.4 × 10-16 W Hz-0.5 and thus within the goal of 1.5 × 10-16 W Hz-0.5.

The realization of a large (40x32) pixel sub-array on a 3-inch silicon wafer brings unique challenges involving the integration of a variety of microfabrication techniques. Design, development and fabrication procedures are described, with conventional MEMS techniques in silicon being used where possible. High resolution imaging in the sub-millimetre range requires a pixel size of the order of one millimetre with a high signal/noise ratio detector, which must be addressed at cryogenic temperatures via a very low noise amplifying system. This has been realized using a combination of Transition Edge Sensors (TES) with amplification and multiplexing (MUX) by Superconducting Quantum Interference Devices (SQUID), which imposes particular requirements in the method of construction. This paper describes the details of the technologies used to overcome the conflicting demands of the different elements. The need to operate at millikelvin temperatures limits the materials that can be selected. Particular attention has been paid to the stresses induced in the structure by overlying films, bump bonding and any thermal processing.

SCUBA-2, which replaces SCUBA (the Submillimeter Common User Bolometer Array) on the James Clerk Maxwell Telescope (JCMT) in 2006, is a large-format bolometer array for submillimeter astronomy. Unlike previous detectors which have used discrete bolometers, SCUBA-2 has two dc-coupled, monolithic, filled arrays with a total of ~10,000 bolometers. It will offer simultaneous imaging of a 50 sq-arcmin field of view at wavelengths of 850 and 450 microns. SCUBA-2 is expected to have a huge impact on the study of galaxy formation and evolution in the early Universe as well as star and planet formation in our own Galaxy. Mapping the sky to the same S/N up to 1000 times faster than SCUBA, it will also act as a pathfinder for the new submillimeter interferometers such as ALMA. SCUBA-2's absorber-coupled pixels use superconducting transition edge sensors operating at 120 mK for performance limited by the sky background photon noise. The monolithic silicon detector arrays are deep-etched by the Bosch process to isolate the pixels on silicon nitride membranes. Electrical connections are made through indium bump bonds to a SQUID time-domain multiplexer (MUX). We give an overview of the SCUBA-2 system and an update on its status, and describe some of the technological innovations that make this unique instrument possible., 16 pages, 14 figures, Invited talk at SPIE Glasgow 21-25 June 2004, Conference 5498

SCUBA-2 is the next-generation replacement for SCUBA (Sub-millimetre Common User Bolometer Array) on the James Clerk Maxwell Telescope. Operating at 450 and 850 microns, SCUBA-2 fills the focal plane of the telescope with fully-sampled, monolithic bolometer arrays. Each SCUBA-2 pixel uses a quarter-wave slab of silicon with an implanted resistive layer and backshort as an absorber and a superconducting transition edge sensor as a thermometer. In order to verify and optimize the pixel design, we have investigated the electromagnetic behaviour of the detectors, using both a simple transmission-line model and Ansoft HFSS, a finite-element electromagnetic simulator. We used the transmission line model to fit transmission measurements of doped wafers and determined the correct implant dose for the absorbing layer. The more detailed HFSS modelling yielded some unexpected results which led us to modify the pixel design. We also verified that the detectors suffered little loss of sensitivity for off-axis angles up to about 30 degrees., Comment: 13 pages, 14 figures, SPIE Glasgow 21-25 June 2004, Conference 5498

SCUBA-2, which replaces the Submillimetre Common User Bolometer Array (SCUBA) (Mon. Not. R. Astron. Soc. 303 (1999) 659) on the James Clerk Maxwell telescope in 2006, will be the first CCD-like array for submillimeter astronomy. Unlike previous detectors which have used discrete bolometers, SCUBA-2 has two DC-coupled, monolithic, filled arrays with a total of 10,000 bolometers. It will offer simultaneous imaging of an 8A—8 arcmin field of view at wavelengths of 850 and 450 I¼m. SCUBA-2 is expected to have a huge impact on the study of galaxy formation and evolution in the early Universe as well as star and planet formation in our own Galaxy. Mapping the sky to the same S/N up to 1000 times faster than SCUBA, it will also act as a pathfinder for the new submillimetre interferometers such as ALMA. SCUBA-2's absorber-coupled pixels use superconducting transition edge sensors (Ph.D. Thesis, Stanford, 1995) operating at 120 mK for photon noise limited performance. The monolithic silicon detector arrays are deep-etched by the Bosch process to isolate the pixels on silicon nitride membranes (Nucl. Instr. and Meth. A, these proceedings). Electrical connections are made through indium bump bonds to a backplane that incorporates a SQUID time-domain multiplexer. We describe the key technologies that make SCUBA-2 possible and give an update on the considerable progress in the detector development and instrument design that has taken place over the last 2 years

SCUBA-2 is a second generation, wide-field submillimeter camera under development for the James Clerk Maxwell Telescope. With over 12,000 pixels, in two arrays, SCUBA-2 will map the submillimeter sky ~1000 times faster than the current SCUBA instrument to the same signal-to-noise. Many areas of astronomy will benefit from such a highly sensitive survey instrument: from studies of galaxy formation and evolution in the early Universe to understanding star and planet formation in our own Galaxy. Due to be operational in 2006, SCUBA-2 will also act as a "pathfinder" for the new generation of submillimeter interferometers (such as ALMA) by performing large-area surveys to an unprecedented depth. The challenge of developing the detectors and multiplexer is discussed in this paper.

Direct bonding of two mirror-polished wafers, without any external applied energy and at low temperature, is an attractive technique for the new generation of ICs, due to the flexibility that the technique offers. This technique can be used for advanced CMOS applications and for MEMS ones, that are MOS compatible. The bonded structure can be obtained using wet or dry activation techniques. The aim of the paper is to provide a method that assures pairs of bonded wafers in case of using a normal thick wafer (/spl sim/300 /spl mu/m) and a thin one (less than 100 /spl mu/m).

We outline the need for SCUBA 2, its goals and specifications. We give reasons for the choice of the low temperature detector technology of TES arrays and SQUID multiplexers, and describe our pixel and array architecture and progress on the project to date.

Tristate antiferroelectric and v-shaped liquid crystal materials have recently offered the promise of both the fast switching of ferroelectric materials and the analogue switching of nematic materials at drive voltages compatible with those available from standard CMOS technology thereby making them, at least in principle, suitable for consideration in microdisplay and other photonic applications. AFLC development is in its early stages and the materials are not yet mature enough for widespread commercial use. The object of the ESPRIT funded MINDIS project has been to evaluate AF-LCoS technology. The electro-optical characteristics of a number of experimental materials have been experimentally measured in test cells that emulate the situation of a silicon backplane (e.g., aluminum reflective back electrode etc). Some candidate materials been shown to exhibit high contrast, uniformity and repeatability. A CMOS active matrix backplane with 1000 line resolution has been designed and fabricated. The backplane is capable of operating in digital or analogue modes for FLC and AFLC respectively. Planarization techniques have been applied to the CMOS wafers but planarization has been shown to be more problematic than with previous backplanes. The reasons for this are discussed. The technology has been theoretically evaluated for use in microdisplays for both projection and near-to-eye applications.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

A protein microarray hybridisation system has been implemented by employing patterned hydrophobic thin films on hydrophilic substrates as a means of confinement for aqueous samples. This approach has the ability to handle, and keep separate, small sample volumes of just a few microlitres. In addition, the system is more straightforward to use than the existing multi-well gasket solution. The paper describes the fabrication method and the system is demonstrated for a model protein microarray assay.

The tides on the coasts of India present a marked difference from those on our own coasts in the large amount of diurnal inequality to which they are subject. My attention was first directed to the subject in the course of an engineering survey of the Harbour of Kurrachee which I made in 1857-58, when I obtained between three and four months’ continuous observations, a copy of which is deposited with the Royal Society. Subsequently I obtained from the Admiralty, through the kindness of Captain Burdwood, R. N., the loan of the records of three years’ observations taken at Bombay in 1846, 1847, and 1848. Of these I plotted in a series of continuous curves the records for 1846, and deposited them, at the Astronomer Royal’s request, at the Royal Observatory, Greenwich. These records, however, are not perfect. They were made by a self-acting machine, the adjustment of which does not appear to have been always accurately pre­served; and I hope that they will be superseded as data for investigation by a better record 'for the year 1868. Taking them as they were, however, I discussed them to obtain the semimonthly curves of semidiurnal tide, and also formulæ for the approxi­mate determination of diurnal tide.