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close this bookEco-restructuring: Implications for sustainable development (UNU, 1998, 417 pages)
close this folderPart I: Restructuring resource use
close this folder4. Materials futures: Pollution prevention, recycling, and improved functionality
View the document(introductory text...)
View the documentEditor's introduction
View the documentBackground
View the documentStrategies to increase materials productivity
View the documentMaterials technology
View the documentMaterial attributes
View the documentMaterial performance trends
View the documentConclusions
View the documentNotes
View the documentReferences

Conclusions

Materials are the underpinnings of technology - not only figuratively but literally. Some of the most important of all technological "breakthroughs" were associated with materials. The ability to make hard, impervious ceramic pots for the storage of liquids and seeds was one of the first requisites of urban civilization, around 8000 BC. The "Bronze" age and the "Iron" age were major technological milestones. The discoveries of paper and glass (not only for windows but, perhaps more important, for lenses) were only a little less significant in their time. Iron tools and weapons are an enormous improvement over bronze tools, but require much more advanced methods of smelting and working. Steel is as much an improvement over older forms of iron as iron was over bronze. The historian Elton Morrison called steel "almost the greatest invention," with some justice.

However, in some sense the "age of materials" is now past and the "age of information" is upon us. To be sure, most traditional uses of basic materials will continue for many decades, with gradual but cumulative reductions in the sheer mass of materials required for most purposes. Materials of all kinds are becoming more sophisticated and "information intensive," in the sense that they offer more service to the end-user.

But greatly overshadowing this rather broad trend is the enormously rapid increase in the uses of materials specifically for purposes of energy conversion (e.g. magnets, photovoltaics) and processing or storing information. The semiconductors and ferrites constitute the two obvious examples of the latter, but it can be argued that the dominant trend of the future is toward the development of materials that are "information intensive" in this narrower sense. A rough tabulation of the materials of greatest research interest today is given in table 4.7. The degree of sophistication and information content of these materials is continually increasing (fig. 4.14). But they will also be more difficult to produce and to recycle. This will induce increasing interest in re-use and remanufacturing in coming decades.

Table 4.7 Breakthroughs expected in serials

Field

Technological need

Breakthrough technology

Materials

Communications

Large-volume transmission

Milliwaves, laser beams

Compound semiconductors (InP, GaAIAs, etc.)


Long-distance transmission

Low-loss optical fibre

Non-silicic material

Information-processing

High-speed operations

Compound semiconductors ICs

Compound semiconductors (GaAs, InP, etc.)



Josephson junction device

Superconductive materials (alloys, compounds)


High-density recording

Perpendicular magnetic recording

Perpendicular magnetized film



Magneto-optic recording

Magneto-optic recording materials



Molecular memory

High polymers, biological substances (protein)

Instrumentation and control

Improvement in sensing performance

Josephson junction device

Superconductive materials (alloys, compounds, etc.)



Biosensor

Biological (micro-organisms, enzymes, etc.)


Improved resistance to environmental conditions

Devices more resistant to environmental conditions

Compound semiconductors (GaAs, InP, etc.)

Energy conversion

Solar energy, especially in remote areas

Photovoltaics

Silicon (crystalline or amorphous) Ga-As, Cd-Te, Cu-In, Se


More efficient generators, transmission lines

Superconductivity

Cu-Ba-La-O. Other methane oxygen compounds

Transportation

Magnetic levitation

Ferromagnets

Sm-Co, Nd-Fe-B



Superconductors

Cu-Ba-La-O. Other metallic oxygen compounds


Fig. 4.14 Relation between the quantity of materials in a product and its information content