Article - Issue 13, August 2002
The MacRobert Award 2002
The MacRobert Award for innovation in engineering is unusual in that it can be awarded to an entry from any area of engineering or technology. The aim of the Award is to recognise the innovative achievements of an individual or team, and to publicise these to a wider audience.
Now in its 33rd year, the award is open to individuals or teams of up to five people from any size of company or institution who can show that they have made a major engineering breakthrough and have exploited it commercially.
Originally founded by the MacRobert Trusts, the Award is now presented by The Royal Academy of Engineering, a prize fund having been established with donations from the MacRobert Trusts, The Royal Academy of Engineering and British industry. Previous winners include Sensaura Ltd for 3-D positional audio (2001), Johnson Matthey for the continuously regenerating trap to control diesel particulate emissions (2000) and Buro Happold for the roof structure of the Millennium dome (1999).
The competition is very strong, as the submissions must meet a number of criteria. In order to be considered for the MacRobert Award, the subject of the submission must be sufficiently innovative, have had commercial success and be of benefit to society. A panel of judges review all submissions and visit the shortlisted companies in order to choose the winner. The judges are drawn from all areas of engineering, each bringing their own expertise to the task.
While the competition is stiff, the rewards are many. The winning team receives a gold medal, £50,000 and the opportunity to mount an exhibition at the Science Museum. Dr Alastair Sibbald, team leader of Sensaura Ltd, winner of the 2001 MacRobert Award, says of the benefits of winning, ‘Winning the 2001 MacRobert Award was a marvellous climax to the ten years of research, development and marketing effort that went into creating Sensaura 3D Audio. Personally speaking, winning the award was truly a momentous, once-in-a-lifetime experience that I shall never forget.
The 2001 MacRobert Award generated a great sense of achievement that permeated throughout our laboratories and sister companies, and it created worldwide publicity that has been very beneficial for our business. Company shareholders have welcomed the Award warmly, and it creates an immediate sense of confidence in our new licensees.’
This year’s finalists come from very different areas of engineering, illustrating the scope of the Award. The Academy hopes that this will inspire others to apply in the future.
In 1989, researchers at Cambridge University found that passing an electric current through certain polymers makes them emit light. Cambridge Display Technology (CDT) was formed in 1992 to commercialise the technology that evolved from this discovery. Now CDT owns the fundamental intellectual property and expertise in light-emitting polymers (LEPs), a form of Organic Light Emitting Diode (OLED). The OLED display market has been forecast to grow to over $1 billion in revenue by 2007.
Light emitting polymer displays are simple to manufacture, have excellent viewing properties and promise low cost manufacture. By altering the chemistry of the polymer it is possible to produce different colours. Now there is a wide range of colours available covering the whole visible spectrum.
LEP displays are made by applying a thin film of the light-emitting polymer onto a glass or plastic substrate coated with a transparent electrode. A metal electrode is sputtered or evaporated on top of the polymer. Application of an electric field between these two electrodes results in emission of light from the polymer.
Since the original discovery of LEPs in 1989, CDT has made significant progress in establishing LEP technology as a solid technology platform for creating a new class of flat panel displays, which is set to both improve the performance of displays in current applications and revolutionise the nature of future display products and how they are manufactured. A key innovation is the fact that a display can be created by ink-jet printing light emitting polymers on to a sheet of glass or plastic, which offers a very low cost route to colour displays.
CDT’s LEP technology has already been licensed to world-class OEMs, including Philips, Seiko Epson, Osram, Dupont and Delta Electronics, as a route to making lighter, brighter, less power consuming and more responsive displays for next generation products such as mobile phones, PDAs and eventually computer monitors and televisions. Features include reduced power consumption, size, thickness and weight, very wide viewing angle, superior video imaging performance and the potential to produce displays on plastic substrates. As devices can be manufactured on flexible plastic substrates it is possible to make displays that have non-planar shapes. CDT licensees will make the technology commercially available in consumer electronic products this year.
‘From the original discovery of LEPs, CDT has succeeded in attaining major scientific milestones to make the vision for LEP displays an engineering reality,’ said David Fyfe, CEO at CDT. ‘CDT is honoured to have received the 2002 MacRobert Award, not only in recognition of this achievement but also for our continued commitment to delivering engineering advancements in pursuit of new applications for LEP technology into the future. The recent opening of our new £25m LEP manufacturing development centre will ensure we are fully equipped to support our licensees in every aspect of the commercialisation of LEP technology’. Currently, the global production demand for polyethylene is in excess of 45 million tonnes per annum. It is estimated that demand will be approaching 70 million tonnes per annum by 2005, giving a growth rate of around 6% per annum. In response to this demand, BP Chemicals Ltd has developed a revolutionary new way to make polyethylene. Safer and more environmentally friendly than previous manufacturing processes, Innovene High Productivity Technology also doubles the productivity.
One of the limiting factors in the production of polyethylene by gas phase technology is the dissipation of the heat produced by the reaction. In order to achieve this, liquid is introduced into the fluidised bed. Earlier forms of gas phase technology used a mixture of gas and liquid in the reactor. However, there is a limit to the amount of liquid that can be held in the gas stream. Once this limit is reached, heat removal from the fluidised bed is restricted and the operation can become unstable.
High Productivity Gas Phase Technology uses a different method to introduce the liquid; it is vaporised and then injected into the fluidised bed using specially designed nozzles to distribute it effectively. This injection of liquid allows optimal distribution and vaporisation of the liquid in the fluidised bed and allows catalysts and modifiers to be dispersed with the liquid.
The nozzle design was perfected using BP’s unique X-ray imaging facility at Sunbury and the process was scaled up to production quantities at Grangemouth in Scotland and Lavera in France. The X-ray imaging allows the complex fluid-dynamic flow patterns in large-scale test reactors to be captured on video and subsequently analysed. This provides real time moving images of flow patterns within the fluidised bed enabling the injection of liquid from different types of nozzle to be visualised.
This technology can give a more than 100% increase in output from a single reactor. It also lowers the investment costs for new reactors by up to 50% and can be retrofitted to existing plants. The Chevron/Phillips Orange Plant used to produce 100 kilotonnes of polyethylene per year. After the introduction of the Innovene High Productivity conversion package, the output was increased to 240 kilotonnes per year.
There is a 30% reduction in energy consumption using Innovene High Productivity technology. On average there is reduction of 45 kg CO2 produced by using the Innovene High Productivity technology, as compared to previous processes.
‘We have 25 licensees for the Innovene process in 15 countries’, says Mike Power, Process Manager Licensing, who is based at Sunbury. ‘And we commissioned our own new 350 kilotonne a year polyethylene plant in Grangemouth in 2000, which is now up and running. Innovene High Productivity is a huge breakthrough and it demonstrates BP’s commitment and ability to offer leading edge technology in one of the world’s most competitive markets.’
The team led by Mott MacDonald were responsible for one of the most daring civil engineering projects ever attempted. Three full-size interstate highway tunnels, the largest well over 100 metres long, each with sections weighing up to 30,000 tonnes, were jacked under an operating commuter railway in downtown Boston as part of the Central Artery Project to relieve traffic congestion in the city centre.
The tunnel jacking scheme – a crucial component of the overall project, which became known in Boston as the ‘Big Dig’ – faced many challenges but the benefits were huge if the engineers could pull it off. Mott MacDonald proposed jacking, or ‘sliding’, the tunnels into position rather than the conventional ‘cut and cover’ tunnelling, which would have meant relocating the railway five times! With seven interconnecting rail tracks carrying over 40,000 people a day, this was a non-starter from both safety and railway operational points of view. The Mott MacDonald proposal generated intense interest but it called for a quantum leap in scale to construct the world’s largest jacked tunnel project – with the three tunnels each ten times bigger than any ever built before in the USA. However, it meant that the railway could keep running the whole time, even though it was just two metres above the works in places. To carry out the tunnel jacking operation, three concrete jacking pits were dug and tunnel boxes 24 metres (80 feet) wide and 12 metres (40 feet) high were built inside the pits. The plan was to break the head ends of the concrete pits and push the tunnel boxes into place with massive hydraulic jacks. In order to move the tunnel box along once it was inside the jacking pit, crews broke the head end of the pit, removed three feet of soil and pushed the tunnel box ahead.
‘The ground itself was one of the biggest problems,’ says Mott MacDonald transportation director Alan Powderham. ‘It is very soft and full of the artefacts from 200 years of harbourside development, which became major obstacles for our tunnels. The site is right by Boston harbour and is crossed by a waterway as well as the railway lines.’ To stabilise the ground the team decided to freeze it across the whole tunnel zone, creating the world’s largest man-made iceberg – 200,000 m3 of artificial tundra. This was achieved by pumping a cooled brine mixture through the soil via a series of freezing pipes. The team also developed a new anti-drag system above and beneath the tunnel sections using a system of steel ropes to help them slide into place more easily. The soil ahead of the tunnel box was excavated using a road header, a machine with a rotating grinder at the end of a movable arm. The grinder broke the frozen soil apart; this was gathered and removed out the back of the tunnel box. When the soil around the freeze pipes was ground, the pipes were then cut away. Two sets of hydraulic jacks were used to drive the tunnel boxes forward at a rate of three to six feet per day.
The scale and complexity of this project have excited the interest of the general public as well as of engineers. The project has already been awarded the 2000 American Consulting Engineers Council Grand Award for Engineering Excellence for the jacking pits.
The tunnel jacking was completed in February 2001 and the Central Artery Project will be completed in 2005. Designed to take most of Boston’s highway traffic underground, it is the biggest, most demanding infrastructure project the USA has ever undertaken. ‘The project put a huge burden on the city during construction,’ says Alan Powderham, ‘as commuters had to leave their cars at home and use public transport. By avoiding any interruption to the rail service, our tunnel jacking brought real relief to this issue. It also substantially reduced the excavation, minimising transportation of heavily contaminated materials through the city. The other bonus for the rail companies was that they could proceed with overhead electrification during the tunnelling phase.’
Surface Technology Systems plc (STS) has cornered the world market in plasma process equipment that is used to create minute machines with features smaller than the width of a human hair. The company’s etching process is based on a concept invented in Germany by Robert Bosch GmbH and licensed to STS plc for development in 1995. The STS process technology team embraced the new technique and soon realised its huge potential for micromachining silicon in industrial applications. Since then STS has made many innovative improvements to the original idea. The resulting product, the Advanced Silicon Etch process (ASE®), is now the standard for deep silicon etching. This process allows a greater performance and degree of control than was possible with the original ‘Bosch Process’.
The etching process that STS plc has developed uses alternating etching and deposition steps to create deep patterns and trenches in silicon wafers. To achieve this, two different gas compositions are alternated in the reactor. The first gas composition deposits a layer of PTFE-like polymer on the surface of the substrate, and the second gas composition etches the substrate. Plasma chemistry and conditions are altered so that the surfaces parallel to the surface of the wafer, i.e. the bottom of the trench, has the PTFE coating removed at a much higher rate than the rest of the trench. The polymer builds up on the sidewalls and protects them from etching. As a result, etching aspect ratios of 50 to 1 can be achieved. This process can be modified to produce the type of etching needed for specific applications, by altering the plasma chemistry and the etching conditions.
The beauty of the ASE® process is that it creates trenches with virtually vertical walls, while other alternative technologies leave the trenches with shallower, angled walls, far less useful for MEMS applications. The technology uses non-toxic, fluorine-based chemistry, operates at room temperature, and has been shown to be capable of producing MEMS devices at a high volume.
There is a growing need in the industry for having an increased etchrate without sacrificing the precision and control of the ASE® process. Thus the latest version, ASEHRM (high rate) launched in 2001, allows faster etching while maintaining accuracy and degree of control of the ASE® process.
STS has acquired around 80% of the world market for the deep silicon etching applications used in microelectromechanical systems (MEMS). ‘We have sold almost 250 silicon etching chambers,’ says Technology Director Andrew Chambers, ‘whereas our nearest competitor has sold less than 50. The MEMS market is rapidly growing Figure 6: Silicon microturbine assembly etched using the ASE® process at a compound annual growth rate of around 25%, estimated to reach US$68 billion by 2005. Constant innovation is essential to satisfy our customers’ everchanging needs in this exciting emerging market and to maintain our technology lead over our competitors.’
The ASE® and ASEHRM are used to make a wide variety of MEMS, such as tiny silicon turbines, gyroscopes, sensors and switches measuring only a few micrometres across. These MEMS machines are used as components in many industries. Current commercial MEMS-based products manufactured using ASE® include opto-electronic switches, gyroscopes for safety-critical applications such as airbag sensors and radio-frequency MEMS for mobile phones.
Future applications for ASE® technology include ‘Lab on a Chip’ or power generation on a micro scale, for example MIT have investigated using ASE® to etch both the vanes of a microturbine assembly and to release the turbine assembly via a high aspect ratio through-wafer etch. Ultimately this microturbine would form part of a small generator unit to replace battery packs in portable electrical devices.
The Academy would like to encourage applications from a wide range of individuals/teams. Details of how to apply as well as rules and conditions for application are on The Academy’s website at www.raeng.org.uk or contact Dr. Elizabeth Horwitz at The Academy for further details.
Cambridge Display Technology
Innovation: Light-emitting polymers for display applications
Team: Dr David Fyfe, Professor Richard Friend, Dr Jeremy Burroughes, Dr Karl Heeks and Dr Carl Towns
BP Chemicals Ltd
Innovation: Innovene, a new high-productivity polyethylene technology
Team: Jean-Claude Chinh, Dr David Newton and Mike Power
Innovation: Tunnel jacking in Boston Central Artery, USA
Team: Alan Powderham, Stephen Taylor, Christopher Howe, Dr Douglas Allenby and John Ropkins
Surface Technology Systems Plc
Innovation: Development of the ASE® process for deep silicon etch applications
Team: Andrew Chambers, Huma Ashraf, Dr Janet Hopkins and Dr Leslie Lea