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Guest Writer - Gastautor - Gast Schrijver
www.nanoTsunami.com

 

Engineering, Biology, and Nanotechnology

 

 

“The question of whether a computer can think is no more interesting than the question of whether a submarine can swim.” -- Edsger W. Dijkstra.

A dog can herd sheep, smell land mines, pull a sled, guide a blind person, and even warn of oncoming epileptic seizures.

A computer can calculate a spreadsheet, typeset a document, play a video, display web pages, and even predict the weather.

The question of which one is “better” is silly. They're both incredibly useful, and both can be adapted to amazingly diverse tasks. The dog is more adaptable for tasks in the physical world--and does not require engineering to learn a new task, only a bit of training. But the closest a dog will ever come to displaying web pages is fetching the newspaper.

Engineering takes a direct approach to solving tasks that can be described with precision. If the engineering is sound, the designs will work as expected.
Engineered designs can then form the building blocks of bigger systems. Precisely mixed alloys make uniform girders that can be built into reliable bridges. Computer chips are so predictable that a million different computers running the same computer program can reliably get the same result. For simple problems, engineering is the way to go.

Biology has never taken a direct approach, because it has never had a goal. Organisms are not designed for their environment; they are simply the best tiny fraction of uncountable attempts to survive and replicate.
Over billions of years and a vast spectrum of environments and organisms, the process of trial and error has accumulated an awesome array of solutions to an astonishing diversity of problems.

Until recently, biology has been the only agent that was capable of making complicated structures at the nanoscale. Not only complicated structures, but self-reproducing structures: tiny cells that can use simple chemicals to make more cells, and large organisms made of trillions of cells that can move, manipulate their environment, and even think. (The human brain has been called the most complex object in the known universe.) It is tempting to think that biology is magic.
Indeed, until the mid-1800's, it was thought that organic chemicals could not be synthesized from inorganic ones except within the body of a living organism.

The belief that there is something magical or mystical about life is called “vitalism,” and its echoes are still with us today. We now know that any organic chemical can be made from inorganic molecules or atoms.

But just last year, I heard a speaker—at a futurist conference, no less—advance the theory that DNA and protein are the only molecules that can support self-replication. Likewise, many people seem to believe that the functionality of life, the way it solves problems, is somehow inherently better than engineering: that life can do things inaccessible to engineering, and the best we can do is to copy its techniques. Any engineering design that does not use all the techniques of biology is considered to be somehow lacking.

If we see people scraping and painting a bridge to avoid rust, we may think how much better biology is than engineering: the things we build require maintenance, while biology can repair itself. Then, when we see a remora cleaning parasites off a shark, we think again that biology is better than engineering: we build isolated special-purpose machines, while biology develops webs of mutual support. But in fact, the remora is performing the same function as the bridge painters. If we want to think that biology is better, it's easy to find evidence. But a closer look shows that in many cases, biology and engineering already use the same techniques.

Biology does use some techniques that engineering generally does not.
Because biology develops by trial and error, it can develop complicated and finely-tuned interactions between its components. A muscle contracts when it's signaled by nerves. It also plays a role in maintaining the proper balance of nutrients in the blood. It generates heat, which the body can use to maintain its temperature. And the contraction of muscles helps to pump the lymph. A muscle can do all this because it is made of incredibly intricate cells, and embedded in a tightly-integrated body. Engineered devices tend to be simpler, with one component performing only one function. But there are exceptions.

The engine of your car also warms the heater. And the electricity that it generates to run its spark plugs and fuel pump also powers the headlights.

Complexity deserves a special mention. Many non-engineered systems are complex, while few engineered systems are. A complex system is one where slightly different inputs can produce radically different outputs.

Engineers like things simple and predictable, so it's no surprise that engineers try to avoid complexity. Does this mean that biology is better? No, biology usually avoids complexity too. Even complex systems are predictable some of the time—otherwise, they'd be random.

Biology is full of feedback loops with the sole function of keeping complex systems from running off the rails. And it's not as though engineered devices are incapable of using complexity. Turbulence is complex. And turbulence is a great way to mix substances together.

Your car's engine is finely sculpted to create turbulence to mix the fuel and the air.

Biology flirts with complexity in a way that engineering does not.
Protein folding, in which a linear chain of peptides folds into a 3D protein shape, is complex. If you change a single peptide in the protein, it will often fold to a very similar shape—but sometimes will make a completely different one. This is very useful in evolving systems, because it allows a single system to produce both small and large changes. But we like our products to be predictable: we would not want one in a thousand cars sold to have five wheels, just so we could test if five was better than four. Evolution is beginning to be used in design, but it will probably never be used in the manufacture of final products.

Copying the techniques of life is called “biomimesis.” There's nothing wrong with it, in moderation. Airplanes and birds both have wings. But airplane wings do not have feathers, and airplanes do not digest seeds in mid-air for fuel. Biology has developed some techniques that we would do well to copy. But human engineers have also developed some techniques that biology never invented. And many of biology's techniques are inefficient or simply unnecessary in many situations.
Sharks might not need remoras if they shed their skin periodically, as some trees and reptiles do.

The design of nanomachines and nanosystems has been a focus of controversy. Many scientists think that nanomachines should try to duplicate biology: that the techniques of biology are the best, or even the only, techniques that can work at the nanometer scale. Certainly, the size of a device will have an effect on its function. But the device's materials also have an effect. The materials of biology are quite specialized. Just a few chemicals, arranged in different patterns, are enough to make an entire organism. But organic chemicals are not the only kind of chemicals that can make nanoscale structures.

Organics are not very stiff; they vibrate and even change shape. They float in water, and the vibrations move chemicals through the water from one reaction site to another.

A few researchers have proposed building systems out of a different kind of chemistry and machinery. Built of much stiffer materials, and operating in vacuum or inert gas rather than water, it would be able to manufacture substances that biology cannot, such as diamond. This has been widely criticized: how could stiff molecular machines work while fighting the vibrations that drive biological chemicals from place to place? But in fact, even in a cell, chemicals are often actively transported by molecular motors rather than being allowed to diffuse randomly. And even the stiff machine designs use vibration when it is helpful; for example, a machine designed to bind and move molecules might jam if it grabbed the wrong molecule, and Drexler has calculated that thermal noise could be effective at un-jamming it. (See Nanosystems section 13.2.1.d.)

Engineering and biology alike are very good at ignoring effects that are irrelevant to their function. Engineers often find it easier to build systems a little bit more robustly, so that no action is necessary to keep them working as designed in a variety of conditions. Biology, being more complicated and delicate, often has to actively compensate or resist things that would disrupt its systems. So for the most part, stiff machines would not “fight” vibrations—they'd simply ignore them.

Biology still has a few tricks we have not learned. Embryology, immunology, and the regulation of gene expression are still largely mysterious to us. We have not yet built a system with as much complexity as an insect, so we cannot know whether there are techniques we haven't even noticed yet that help the insect deal with its environment effectively. But even with the tricks we already know, we can build machines far more powerful—for limited applications—than biology could hope to match. (How many horses would fit under the hood of a 300-horsepower sports car?) These tricks and techniques, with suitable choices and modifications, will work fine even at the molecular scale. Engineering and biology techniques overlap substantially, and engineering already has enough techniques to build complete machine systems—even self-contained manufacturing systems—out of molecules.

This may be threatening to some people, who would rather see biology retain its mystery and preeminence. But at the molecular level, biology is just machines and structures.

The Center for Responsible Nanotechnology(TM) (CRN) is an affiliate of World Care(R), an international, non-profit, 501(c)3 organization. All donations to CRN are handled through World Care. The opinions expressed by CRN do not necessarily reflect those of World Care.


Chris has studied nanotechnology and molecular manufacturing for more than a decade. After successful careers in software engineering and dyslexia correction, Chris co-founded the Center for Responsible Nanotechnology in 2002, where he is Director of Research. Chris holds an MS in Computer Science from Stanford University.

Copyright © 2004 Chris Phoenix


The Center for Responsible Nanotechnology(TM) (CRN) is an affiliate of World Care(R), an international, non-profit, 501(c)3 organization. All donations to CRN are handled through World Care. The opinions expressed by CRN do not necessarily reflect those of World Care

 


Patric Salomon

 

 

Worldwide Services and Infrastructure
for Nano- and Microproduction

by Patric Salomon




& Henne van Heeren (NL)

 

NanoTsunami readers know that a large number of applications and markets could be served by products based on the various micro nano technologies (MNT). However, the variety of MNT manufacturing technologies also poses a threat to the commercial breakthrough of MNT. With so many technologies available, most of them not yet standardised, and non-availability of standard equipment for several of them, how can MNT become commercially successful?

In certain high-volume markets, such as automotive, computer peripherals, and communications, the advantages of MNT were able to overcome the problems that follow technological diversification. The authors believe that only a good infrastructure of design houses, foundries, package/assembly providers and equipment suppliers is able to satisfy the demand in design, prototyping, and (mass-) production in all the MNT fields. This infrastructure is needed to provide an efficient route to commercialisation.


Fig.1: Services and infrastructure needed for the commercialisation of MNT

 

Foundries and Design Houses play a major role in the supply chain. Foundries, provide the infrastructure to prototype, fabricate and mass-produce the designs emanating from the design houses and other companies. The reason for the customers to rely on foundries can be diverse: ranging from pure financial reasons (investment, cost-price) to technical (availability of required technology). The desire to have a second source of supply can also be a reason for outsourcing. A ‘fabless’ design house can generally be described as the catalyst that enables ideas or concepts to migrate towards commercialisation. In this context, the fabless design organisation manages the process of technology transfer from R&D to a production line.

Packaging suppliers are another, often not very visible, part of the infrastructure. Although the diversity in packaging and assembly for MST/MEMS is notably high, they can be classified into the following four generic groups:


• Standard available packaging and assembly technologies. Techniques, which can only be used in a limited number of cases, often hindered by the (mechanical) sensitivity of the product, the small dimensions or the special demands in the field of interconnections with the outer world.

• Specialised assembly, often with special technologies ensuring ultra precise positioning and/or very careful handling.

• Adapted standard packaging, where use is made of the cost effective and high quality processing capabilities established for the high-volume electronics industry. The main trend here is to use a die protecting method during plastic moulding. Closure for sealing the package is achieved afterwards. The lid can be used to accommodate feed troughs for optical or fluidics access.

• Waferscale package. This method promises a, potentially, low cost solution which circumvents problems associated with handling sensitive products in an assembly line, by providing protection at an early stage of the processing.

Supporting the professional infrastructure are the equipment and material suppliers. The emerging markets for MST/MEMS (Micro Systems Technologies / Micro-Electro-Mechanical Systems) products have created a demand for specialised equipment. The first to fulfil that demand were suppliers of dedicated MST/MEMS tools including Deep Reactive Ion Etchers (DRIE), waferbonders and backside aligners. Those companies (STS, Aldixen, AML, EV Group and Suss Microtec) are still in the forefront of this market. Spin-offs from universities were started to fulfil (niche) demands, whilst established companies entered this arena at a later stage, offering adapted processing tools developed for other industries, such as, those specialising in thin film processing. More interestingly, even the (large) semiconductor equipment manufacturers have begun to show an interest. Within this context, there is now available a mixture of general equipment facilities, designed and developed for other applications such as semiconductors and also equipment adapted or specially tailored for Micro-Nano Technologies (MNT) production. It is noticeable that, although Europe (particularly Germany) is relatively strong in the area of MNT Back End equipment, the presence of European manufacturers is less impressive in Front End equipment production and almost non-existent in the area of nanotechnology.


Fig.2: Suppliers of MNT production equipment

 

When nanotechnologies are taken into account to be used with microproduction, the manufacturing technologies become even more diverse. To investigate the market and distinguish trends, the authors categorised the production processes for nanotechnology-based products into four areas (Fig. 3):

• Top down nanotechnology: Top down nanotechnology is mainly based on processes and equipment for high-end lithography and similar equipment. Technologies and equipment are aiming at producing large quantities of products, mostly on flat substrates.
• Bottom up technologies: Bottom up technology involves the building up of nanotechnology products from atom level, by either mechanical manipulation (using Scanning Probe Microscopes) or with molecules assembling other molecules (Molecular Self Assembly).
• Nanoparticle production: In nanoparticle production extended traditional physical and chemical methods are utilised to create particles with smaller sizes and special properties.
• Nanotube production processes. Nanotubes are seen as a very promising material due to its unique properties.


Fig.3: Nanoproduction technologies

 

 

It should be noted that the top down and bottom up approach (except Molecular Self Assembly) are mostly equipment oriented. Molecular Self Assembly, nanoparticle and nanotube production are much more process oriented. Top-down and bottom-up nanotechnology equipment benefit from the equipment infrastructure for semiconductor lithography and deposition and the ample availability of Scanning Probe Microscopes. Most of the development of processes for the production of nanoparticles is done in-house. The equipment market for nanoparticle production is not well developed, although it benefits from knowledge from the chemical/physical process equipment market.

Conclusion

The use of MNT based products is growing in a number of application and markets, ranging from life science to telecommunications. Besides a few notable exceptions, the MNT market is still a sum of niche markets. There is a general consensus that the overall market will grow, but that commercialisation will take longer than was anticipated a few years ago.

Packaging still remains a bottleneck introduced, belatedly, at the end of the design cycle, and often delaying or even preventing industrialisation and commercialisation. It is well known that selecting the appropriate packaging method may be the decisive factor that determines a product’s success or its premature failure. Choosing the right technology, therefore, is not a marginal concern, but pivotal to the product design. The existence of professional suppliers of packaging and assembly is an essential element in the supply chain and critical for the manufacturing and commercialisation of MNT-based products. In addition, the incorporation of packaging and assembly techniques at the front-end of the engineering cycle will pay back in terms of financial savings and shorter timescales to market. Methodologies for a ‘design for micro nano manufacturing’ approach are under development.

Many companies working in the field of nanotechnology aim at the extension of semiconductor equipment to suit the market needs (the so-called “top down” approach). Also several companies are offering equipment based on chemical and physical processes for the production of small particles and nanotubes. The “bottom up” approach, aiming to build nanotechnology products practically atom by atom, is less prevalent. There is an ample supply of Scanning Probe Microscopy based tools, but such instruments are not yet able to combine nanotechnology precision with industrial volume demand. Processes for molecular self-assembly, which are potentially more suitable for economical mass production, are still in development and far from industrialisation.

The industry as a whole could benefit from exchange of information and consensus over process and product specifications and related equipment specifications. It is however unlikely that industry wide roadmaps will play a role similar to the one played for the semiconductor industry. This is due to the fact that there is no MNT equivalent to the transistor and it is not to be expected there will be one. It is more likely, however, that application roadmaps will extend their influence into the MNT arena. In essence, the customers and the end users will determinate the roadmap and not the (equipment) suppliers. This will undoubtedly lead to a more diverse set of processes, equipment and standards in MNT as compared to semiconductors. A situation that is likely to create a much wider range of opportunities for smaller (equipment and material) suppliers, as long as they are able to combine flexibility with quality and staying power. However this lack of commonly shared technology platforms is a serious threat to the realisation of reliable and low cost products.

In addition to the availability of a services infrastructure, the availability of a wide ranging, industry-based intelligence information is of vital importance in order to optimally select from this array of enabling capabilities. This array of information is provided through the enablingMNT Industry Review series: Design and Engineering Companies, Foundries, Packaging and Assembly Suppliers, Equipment Suppliers (MEMS Front-End, Back-End, Nanofabrication), MNT Web Directories / On-line Communication Channels, and Materials for MST/MEMS Production. Reports on Test and Measurement Services & Equipment and Design Tools are underway. All reviews cover worldwide activities and sell at € 280 each.

Customised research and consulting services offered by enablingMNT range from market research, business development support and partner search for industrial customers to benchmarking and exploitation strategy development for public bodies.

Contact:
Patric Salomon, Germany
Henne van Heeren, The Netherlands
E-mail: info@enablingMNT.com

Link : enablingMNT

 

Copyright © 2004 Patric Salomon

Chris Phoenix

CRN Director of Research

 

 
 


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