Sciovis was formed in 2005 to provide a consultancy service in the area of advanced science and technology with particular relevance to the defence and security arenas
Some illustrative technology themes
Sciovis was formed in 2005 by Keith Lewis to provide a consultancy service in the area of advanced science and technology with particular relevance to the Defence and Security arenas. The company builds on experience gained by its founder in roles demanding advocacy, political astuteness, probity and diligence, which have required him to interact effectively with scientists, military personnel, academic groups and industry. He is a strategic thinker, with detailed technical expertise in cross-disciplinary areas of activity and has access to a well-established network of contacts, both in the UK and overseas. As a former Technical Director within QinetiQ he also has an awareness of business environments due to his involvement in shaping technical strategy and ensuring cohesion across the organisation.
Sciovis can provide advice at different levels in a number of areas, ranging from technical innovation to the application of technology for meeting demanding requirements in Security and Defence.
Some illustrative technology themes
The role of electro-optics in modern warfare. The shift in emphasis from Cold War scenarios to urban conflict has been a major factor in driving technology change in recent years, bringing with it the desire to exploit systems that support rapidly deployable force projection. Optical systems, from the simplest infra-red sensor to the most complex satellite imaging system are ubiquitous in the defence arena and frequently provide the key differentiator in ensuring operational supremacy. The evolving nature of network enabled capability (or network centric operations in the USA) is also placing increasing demands on sensor systems and their associate communication networks. Added to this are the problems posed by asymmetry and the need for force multipliers to meet requirements for peacekeeping in the urban theatre which are becoming an increasingly important feature of coalition force operations.
Advanced optical sensors play a key role in surveillance, targetting and communication systems. For example, within the urban environment, compact sensors are required for the dismounted soldier to enable operations to proceed at all times of day and night and to provide the ability to discriminate genuine military targets from the civilian population. There is an urgent need to provide a means of detecting improvised explosive devices and hitherto largely unexplored parts of the electromagnetic spectrum are being examined to provide the ability to detect hidden devices. The problems of mine warfare are also significant and new techniques are emerging with the promise of improving the rapid location of buried mines.
With the ability to sense in electromagnetic wavebands including ultra-violet, visible, near infra-red, infra-red, millimetre wave/Thz and RF bands (eg synthetic aperture radar SAR), the signal processing and communication burden of the fused output of such sensor systems will eventually require communication channels capable of handling potential data rates of hundreds of tera-bits per second.
Lasers have found an increasing role in military manoeuvre as a result of their exploitation in rangefinders, in non-cooperative target identification, target designation and more recently in providing the underpinning technology for 3-dimensional imaging and free-space communication systems. Short pulse lasers are the basic enabler for range-gated imagery but whilst systems have been demonstrated operating at 1.06Ám, more recently activity has shifted to the use of 1.55Ám eye-safe source technology, exploiting technology emerging from the commercial fibre optics telecommunications arena. Lasers also provide the basis of systems being developed for directed infra-red countermeasures to deal with the threat of advanced missile systems.
Smart Optical Materials are materials whose optical characteristics change in a predictable manner in response to external stimuli such as temperature rise, electric field, laser irradiation etc. The materials already underpin a multi-billion dollar industry across the world, encompassing many product applications covering a wide range of markets (eg telecommunications, data storage, data and information display etc). Yet in many ways, the materials are still evolving, with new effects and device architectures continually being developed. Significantly, these often emerge because of the multi-disciplinary nature of the research activity, which cuts across the boundaries of traditional disciplines (chemistry, physics, biology etc). The ensuring products are often enablers, underpinning diverse markets, and are limited only by the vision of the developer. The process of cross-disciplinary innovation has become a major focus not just for government agencies and multi-national organisations, but also for small entrepreneurial groups developing their own market niches.
Optical systems process light by the manipulation of amplitude, frequency, phase, polarisation, separately or in combination. The optical components frequently required for the various manipulative functions are usually passive devices and cannot adapt their characteristics as a function of changing input parameters. On the other hand, the availability of active devices can provide benefit in enhancing the performance characteristics of the system. For example, smart optical devices could provide the basis for digitisation, non-linear compression, beam forming or switching between different processing paths in telecommunication networks. Equally well they can protect sensors required for use in an electro-optic-rich battlefield.
The invention of the transistor by William Shockley and his co-workers in 1948 and the resulting advent of solid state electronic devices has shaped modern lifestyles beyond levels that would have been unimaginable even in the early 1960s. Recognising and exploiting technological advances at an early stage is the key to staying ahead in the market place. A further revolution is arguably about to occur, as a result of the exploitation of optical systems for imaging, display, telecommunication, information processing and ultimately computing. Yet again the role played by materials will be very evident in shaping the possibilities for optical devices and system architectures. The significant advances already made in electronics will be enhanced through the development of hybrid devices and systems to satisfy the ever increasing demands for information, intelligence and sophistication that are characteristic of modern lifestyles.
Yet the extent of application of optical devices is in its infancy since most optical systems are assembled from discrete components on a mother-board, in a situation analogous to that pertaining in electronics some 30-40 years ago. However the drivers for the development of highly integrated components are emerging, setting the requirements for multifunctional optical and electronic processing on a single silicon chip.
Biomimetics and Bio-inspiration. By exploring strategies developed by biological organisms to survive in their environments it is possible to develop design rules for the development of synthetic analogues that are inspired by the natural system. Biological systems have evolved over millions of years through processes of natural selection. Elegant strategies have been developed ranging for example from the ultra-tough shells found on certain molluscs which are able to survive the attention of aggressive marine boring worms, to the ubiquitous sensing abilities of insects.
Most organisms have developed strategies for sensing their environment, but no class of organisms exhibits a greater range of adaptations than the arthropods eg Crustacea (crabs, lobsters), Arachnidae (spiders, scorpions), Myriapodia (centipedes, millipedes) and insects. These organisms have developed the ability to detect and monitor a diverse set of stimuli, including thermal, acoustic, chemical, magnetic, attitude and seismic triggers. Sometimes different combinations of sensilla are found in the same organ, for example, enabling insects to locate prey with an uncanny accuracy especially when due regard is taken of their physical size.
In insects, there are two broad types of sensilla, the first related to the cuticle and derived from a single epidermal cell (mechanoreceptors, light receptors, chemoreceptors), whilst the second are internal and sense deformation and stresses (proprioreceptors, chordotontal sensilla etc). Mechanoreceptors are often based on short stiff hairs, which respond to direct deflection. In comparison, campaniform structures sense deflection of a dome shaped plate of cuticle. For acoustic sensing, the male mosquito has fine hairs on the antennae that vibrate in sympathy at specific frequencies. Tympanic organs can also provide for acoustic sensing (eg in Lepidoptera) using a membrane stretched over a tracheal air sac. Such structures has been found to respond at frequencies up to 70kHz.
For acoustic sensing, certain insects have developed highly developed abilities for sound localization. Some species of parasitoid flies (Ormia) do not use vision to track their prey, but can operate at night, locating prey on the basis of sound emission. Researchers have shown that female flies can locate crickets at a range of several meters to an accuracy of a few centimeters. Two ears are located on the thorax of the flies and are composed of two tympanal membranes linked by an exo-skeletal structure. Each auditory organ, which is attached to the tympanal pits has over 100 sensory neurons associated with it. In turn, these are connected to auditory nerves which relay signals to thoracic ganglia in the insect's central nervous system.
In the area of magneto-reception, studies of ants, bees and beetles have revealed some remarkable sensing abilities. For example, mealworm beetles are able to use magnetic fields to orientate their body direction. Studies of other species eg the migratory termitophageous ant Pachycondyla Marginata using SQUID magnetometry, have indicated that the part of the insect with the strongest magnetic characteristics was the antennae. Sensitivity to magnetic fields has been recently been proven to exist in certain lobsters and the indications are that they develop magnetic maps of the environment over distances as large as 10km, indicating fine-scale sensitivity to the earths magnetic fields.
In the case of infra-red reception, studies have highlighted the existence of highly sensitive organs in several species of beetle (eg Melanophila, Merimna, Acanthocnemus). Since the sensitivity of such insect receptors is reportedly as good as cooled photon devices, there is clearly a great deal to be gained if electromechanical or electro-optic analogues of such systems can be developed. There are clear differences between the structures of the sensilla in the cases of Melanophila and Acanthocnemus. In the latter, because of the resemblance of the organ to a tympanic membrane, one possibility is that the insect exploits mechanical resonance effects to maximise the response.
Biological organisms also exploit colour effects to imporve their chances of survival. Processes that give rise to colour fall into three main groups:
Colour due to specific chemical species in the form of pigments;
Structural colour arising from thin film interference or diffractive processes;
Colour generated by bacteria present in the host animal at the cellular level.
Complex architectures have evolved to provide capabilities for the conflicting requirements of signaling and hiding. In some cases, such as in the Abalone shell, color results from the structure developed to provide specific mechanical characteristics. Here, the mollusc has evolved a shell structure that provides for survival of the species in an environment where it can be attacked by shell-boring marine worms. The colour arises because of the lamination of successive aragonite and glycoprotein layers, whose periodicity corresponds to that of a Bragg reflector for radiation in the visible spectrum. In comparison, some butterflies and moths sport brilliant colour schemes using exquisite chitin/air structures, with highly developed morphologies to compensate for angular field-of-view effects.
Some species have developed adaptive capabilities to ensure survival in a predator-rich environment. The most spectacular are found in marine animals, notably the cephalopods such as octopus, cuttlefish and squid. Similar characteristics are found in certain species of fish, notably flounder, which possesses the ability to change both colour and texture in response to its environment.
Colour/texture changes on the skin of a flounder. These two images were taken of the same fish a few seconds apart as it moved from a dark background to rest on an area of light sand.
Such adaptive biological systems have several features in common:
Layer(s) incorporating chromatophores - cells containing absorptive pigments whose shape, size or orientation can vary in response to stimulation
Cellular layers containing iridescent (reflective) pigments that may also respond to hormonal control
Scattering layers that act to change the diffuseness of reflected light, with the ability to hide one or more of the other layers
Basal layers that may be reflective or absorptive (depending on species), which act to provide the baseline appearance of the skin and are generally not adaptive
A sensor system, which provides the stimulus for adaptation via a control system. Here examples exist of electrical control by nervous impulses, and chemical control by signaling compounds (usually hormones) circulating in the bloodstream.
For rapid colour change, the number and location of cells responding to each stimulus needs to be closely coupled and in cuttlefish each chromatophore may be individually innervated. This particular species also has patterns revealed in polarized light that are used for identity, and which can be controlled to some extent through iridophore platelet ultrastructure. Specimens have been found to retreat from their own reflection in a mirror, unless a filter distorts the polarization. This clearly demonstrates the level of complexity that has evolved in Nature over millions of years to ensure the survival of the species.
Free space optical communications. Military users have a need to identify and establish communication links with isolated platforms, groups of soldiers and targets in a wide range of scenarios. Broadcast radio frequency (RF) communication has for some time formed the backbone of robust battlefield communications. Such communication techniques are independent of local weather conditions and have wide coverage. However, it has become widely recognised that the bandwidth available is sometimes inadequate for some data streams, particularly those provided by imaging sensors. A further disadvantage is that it RF emissions can be easily detected by hostile parties, thus limiting usefulness in denied areas and hampering covert operations.
Free space optical communications offer a number of benefits over RF communications notably higher bandwidth, covert operation, lower probability of intercept and the provision of multiple independent, non-interfering channels. These advantages arise partly from the higher carrier frequency but mostly from the greater directionality at optical wavelengths. However, the directionality comes at a cost; a laser pointing system requires mechanically gimballed mirrors, detectors and tracking algorithms to ensure a communications link is maintained. For a conventional symmetrical communications system, both the transmitter and the receiver need to be mechanically tracked to maintain the required signal bandwidth.
There are benefit is exploiting asymmetric optical communications strategies which use a single tracked transmitter/interrogator, and a passive receiver. In this case, the outgoing end of the link is formed from a relatively inexpensive laser transmitter and receiver coupled to a point-and-track system. The other station has a transponder that comprises a retro-reflector located behind an optical modulator, which is controlled by the return data stream.
The transponder can be designed to communicate only when it is interrogated by the beam from the laser transmitter and can be very compact and inexpensive as it has no laser and no tracking unit. This allows for the concept of a local hub comprising the interrogator and many distributed transponders, for example as would be required for enabling covert communication links to unmanned ground sensors.
Such an optical transponder system can allow military forces to identify and track mobile objects accurately, using ground based or airborne interrogation. Given the high communications bandwidth offered by such a solution, other mission data (sensor, voice, imagery) could also be covertly gathered.
There are many different techniques available for the realisation of the optical modulator required for the retroreflecting device. For high data rates, workers in the field have examined the potential of using multiple-quantum well modulators, which are capable of modulation rates in excess of 10Mbps. However considerable advances have been made in recent years in the development of silicon microsystems technology, especially micro-electromechanical systems (MEMS). These have been realised partly as a result of investments in the telecommunications industry driven by the need to develop components (eg switches, modulators, cross connects) for the optical back-bone. Another contributing factor has been the development of the digital light projection engine (DLP) by Texas Instruments which is rapidly overtaking liquid crystal technology as the core element of high performance displays.
Thin Film Optics. Physical processes giving rise to colour have always been of scientific interest. In everyday life, colour effects resulting from optical interference processes are found in examples as diverse as the oil film on water to the brilliancy of certain species of sea shell (Abalone) and butterfly (lepidoptera). At a technological level, optical thin films underpin a multitude of applications since they provide the means of processing light by the manipulation of amplitude, frequency, phase, polarisation, separately or in combination. Thin films are found in all optical systems ranging from the simplest lens to the most complex satellite imaging system. They are also appearing to an increasing extent in the consumer world, for example in novel decorative paints, art-work and as components of technology used to combat the profileration of counterfeit goods.
Within the defence environment, thin film optical devices also play an important role in determining the degree to which complex electro-optic systems survive in the battlefield. For example, transparent erosion-resistant coatings have been developed for the protection of external surfaces of airborne systems to meet critical demands in terms of retained performance over the operational lifetime of the system. Other thin film devices are enablers for the advance of laser technology with requirements for all spectral bands. A major challenge here has been to provide mirror designs capable of surviving the intense fluences existing within laser cavities. The control of emissivity in the infra-red is also becoming a significant factor, not only for military applications, but also in the search for a means of reducing heat losses from buildings and the corresponding impact on the environment.
The optical characteristics of all thin film ensembles are determined by processes of constructive and destructive interference between the multiple layers present in the coating. For any multilayer structure there is considerable flexibility in achieving a set of desired characteistics. In narrow-band rejection filters, the position and bandwidth of rejection lines can be determined precisely, although the effects of varying fields of view have to be taken account of in the design process. The simplest designs exploit stacks of differing materials, each an optical quarter-wave thick. However, modern design and fabrication techniques allow the realisation of very complex structures, with potential benefit in flexibility and reduced insertion losses. Ultimately, the level of complexity is determined by the optical characteristics required in the thin film ensemble, and the cost of manufacture in commercial production.
Optical coatings find their way into a wide range of applications. For example in the area of optical telecommunication, the exploitation of wavelength division multiplexing (WDM) had a major effect on the optical coating industry in the late 1990s. This is still potentially a prime area of opportunity as a general expansion of services occurs as a result of growth in loical area networks, optical links to homes and businesses, expansion in database access, on-line video conferencing and the transmission of integrated voice/ data/video/multimedia.
In the area of wear resistant coatings it is often necessary to combine the mechanical characteristics of thin films with specific optical properties. Whilst the group of oxide materials are capable of producing coatings which are resistant to abrasion, their performance levels fall short of those required for many applications. Thus attention has been paid to the development of other materials, especially for applications where some level of resistance to erosive impact is required. Materials such as silicon carbide, boron carbide, boron phosphide, titanium nitride and diamond-like carbon provide many of the desirable characteristics of wear resistance in bulk materials. However the degree to which such materials can be exploited for optical applications is restricted. For example many of the transition metal nitrides are metallic and indeed can often be found as hard decorative coatings on metals. Titanium nitride in particular has the appearance of gold and can be deposited on a wide range of surfaces, ranging from metals to polymers using reactive sputtering. On the other hand, films of diamond-like carbon (DLC) can be transparent and have been developed for a number of applications ranging from external coatings on infra-red optics on military fighting vehicles to magnetic heads used in computer hard discs.
Opitical thin films also key enablers in energy management and many of the techniques used for the spectral control of solar absorption are based on multilayer thin film structures. With the emphasis being given on increased energy efficiency, such coatings are being sought for both architectural and automotive applications. Some automobile windscreens already incorporate coatings for the control of solar loading on the interior of the vehicle in order to reduce the load on the air-conditioning system.
The growing problem posed by counterfeiting and parallel trading has been a centre of much attention in recent years. With estimates of as much as 7-8% of world trade involving counterfeit goods during the year 2000, brand owners and indeed government offices are becoming more concerned by the extent of proliferation. The figure for the year 2000 compared with a level of 5% in 1999 and $600bn in 1998. The problem is thus growing at an exponential rate. Very few products escape the attention of the counterfeiter, with recognised cases covering computer software, video and CD music, auto and aircraft components, foodstuff, pharmacueticals, sport and leisure wear. US cheque fraud is of the order of $16bn per annum and there is the growing problem of identity fraud (eg through the fraudulent use of passports and driving licences to obtain credit).
Many of the techniques developed to beat the counterfeiter are based on optical effects. Holographic features are commonly found on credit cards and banknotes, but attention has recently been focussed to benefits afforded by the use of colour shifting inks exploiting optical thin films. The technology required to realise such materials is highly capital intensive and arguably beyond the reach of most counterfeiters on a cost effective basis.
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Sciovis currently provides the Research Director for the Electromagnetic Remote Sensing Defence Technology Centre (EMRS DTC). The DTC was set up by the UK Ministry of Defence to enable the rapid exploitation of research work from academia and other research providers to industry in the area of: remote sensing to provide:-
Day & night, all weather capability.
Long range operation.
Rapid, large area search capability.
Detection of low signature targets.
Detection of camouflaged / concealed targets.
Affordable robust systems for military platforms.
Multi function detection & ID capability.
The company also has a close relationship with QinetiQ, which enable its founder to pursue his scientific research interests whilst furthering links already formed with organisations in the USA.
Keith Lewis retired from QinetiQ in 2005 where he was a Technical Director responsible for the integration of Research and Innovation activities within the company's Technology and Products Division. Fields of activity within the Division encompassed a wide range of technologies with business groups involved in micro/nanotechnology, electro-optic products, photonics and lasers, structural composites, metallic materials, smart materials, fuels/lubricants, gas turbine technology and advanced power sources (eg fuel cells).
Activities include the development of research themes with a particular focus on generating disruptive technologies for the defence arena. The major benefactors were Defence Ministries in the UK and the USA, especially the Defense Advanced Research Projects Agency (DARPA). Emphasis was on the establishment of highly innovative solutions in relation to specific requests for proposals and developing the necessary interactions with collaborators and technology providers both in the UK and in the USA.
He also maintained his own field of research with interests ranging from fundamental materials and device research with a high degree of innovation to studies of the vulnerability of military platforms. Defence interests covered sea, land, air and space applications with specific reference to the development of advanced concepts for sensors, sensor protection, signature control and assessments of satellite vulnerability. He is a specialist in the integration of ideas from disparate areas of science and technology, ranging from biomimetics to advanced electro-optics, with concepts finding application not only in defence systems, but also in the commercial arena (eg for anticounterfeiting, optical telecommunications).
He is an active member of the Society of Photo-Instrumentation Engineers (SPIE) and the Materials Research Society (MRS), where he has been instrumental in organising several major scientific symposia and conferences.