New kids on the block

The modern cleanroom is facing a considerable challenge, as design houses look to bring new technologies such as lab-on-a-chip, micro-electro-mechanical systems (MEMS), micro and nanotechnology, photonics, bioelectronics and microfluidics to market. The lines between the traditional R&D cleanroom and large-scale fabrication facility are blurring.

With commercial pressures mounting, the need for UK design houses to be first to market is immense, and delivering a single working prototype is no longer the sole requirement they have of the cleanroom. As a result, design houses are asking cleanrooms to act as a bridge to large scale manufacture, by using materials and instilling processes that can be accurately replicated in high volumes and at low cost in transition to large scale fabrication. The challenge for the cleanroom is coping with the broad array of projects that come through the door. A decade ago the focus was virtually all complementary metal oxide semiconductors (CMOS), but now the trend in the UK is towards diversification. The existing toolsets required to cope with these emerging technologies are already in place, such as top-down nanotechnology to sculpt silicon in order to create nano-devices. This diversification is being fuelled by an influx of innovative technologies with some revolutionary market applications. One such application is demonstrated in a recent MEMS project by Perpetuum, with development and production support from Innos. Perpetuum, founded by a team of scientists at Southampton University funded by IP2IPO and Sulis, recognised that the biggest roadblock to the progress of wireless communications industry is power: either a battery or a connection is required. Batteries, while efficient, need to be recharged or replaced. Perpetuum therefore developed a small electromechanical system the size of a matchbox, consisting of an arrangement of magnets on a vibrating beam, which move past a coil to generate power of up to four milliwatts.

Microgenerators This principle of harvesting kinetic energy from vibrations in the environment and converting it into usable electrical energy was not new; however, the company recognised that if the device could be made smaller, the market for such a product would grow exponentially. For example, imagine a heart pacemaker that uses the patient's own body energy to power it, eliminating the need for a battery and the operations to replace them. Whereas in the 1990s it would perhaps have been feasible for Perpetuum to have attracted funding and built its own cleanroom to conduct the R&D, this is no longer a viable option for the design house. But, with an R&D facility on its doorstep, Perpetuum embarked on the project with Innos. From this original concept, a silicon-embedded version of the device was designed with dimensions of 5mm x 5mm x 1.5mm, that was capable of producing a few hundred microwatts under suitable conditions. This made the heart pacemaker application, among others, a real possibility. The power achieved by this silicon MEMS microgenerator can drive sensors, small micro-processors and RF transmitters, producing a completely self-powered system. However, getting such a product to prototype and finding the right application and getting the product to market are very different objectives. Perpetuum needed to demonstrate that the device could be replicated at considerable volume, and it is here that a common dichotomy for the design house unfolds. R&D cleanrooms have a limited scope of resources, such as labour and physical assets, and are usually able to produce only a handful of prototype devices, otherwise the costs start to spiral. In contrast, large fabricators are strongly yield-defined in that they will only produce hefty numbers of a product in a continuous process. They cannot justify making a handful or even hundreds of a prototype, and this places design houses in a particularly difficult situation. Do they take the huge risk of sending the prototype to manufacture on the basis of a prototype? Will it work? And if it does, who will buy them? Working with a type of hybrid cleanroom facility that could manage this transition, Perpetuum was able to produce the device cost-effectively in low volumes to demonstrate to investors that it could be reproduced with consistent quality when it eventually reaches a fabricator. In the quest to make these technologies and applications available to a wider market, the cost per device is ultimately the deciding factor, and the materials used to produce each device represent a significant part of the cost. Silicon is relatively expensive, but the tolerances are extremely fine in processing. Plastics are far cheaper, but the tolerances are not as tight. Producing a working prototype in silicon is a starting point, and in many instances silicon will suit the end user application perfectly; but if the economies of scale do not measure up then other materials need to be looked at that can meet the requirement at the right price for the right volume. Innos has recently been involved in the transition of a silicon embedded device to be manufactured in pure glass, which can be produced at a fraction of the cost. In practice this device can now be mass-produced in a production line environment, as opposed to working with silicon substrates of four, six or eight inches in diameter. The integration of technologies such as MEMS involves the development of devices that converge both electrical and mechanical components. The fabrication of semiconductors is now about interfacing with the outside world.

Lab-on-a-chip As with MEMs, lab-on-a-chip is another technology on the brink of cross-over into mainstream society, but facing identical product and market forces. It could mean the end of many hospital waiting times; earlier diagnosis; improved healthcare in third world countries, and even a reduction in road traffic accidents. This is advanced technology for the masses: small, disposable single-use devices that can move laboratory processes out of the lab. Consider a blood test where lab-on-a-chip technology could enable every doctor's desk to have a miniaturised machine with the same capability to analyse the properties of a blood sample in seconds. Similarly, road traffic police could be equipped with appliances that test blood or saliva for alcohol and drugs instantaneously.

Bridging the gap Getting applications of these technologies to market continues to be testing because of the lack of potential investors and early adopters willing to take a leap of faith. The industry needs to understand that there is a huge requirement to bridge this clearly apparent gap between design house and manufacturer; it needs the cleanroom to act as a middleman, and not only to reduce the risk of failed mass production due to the restrictions on resources at the research and development lab. The solution to the problem is not just copious equipment in the cleanroom, but the ability to meet any project head on and be prepared for new waves of technology. This needs better scalability and flexibility of resources; top-shelf expertise; and the scope to cope with manufacture of devices in small numbers and to establish partnerships with larger fabricators to support the project through to manufacture and eventually to market. Ideas are abundant and the processes for these new technologies well established, but for cleanrooms to thrive they must learn to understand and support the commercial aspirations of their clients.