How we change what others think, feel, believe and do
TRIZ Part 4
In part 1, we looked at functions, harm, ideality and contradictions that occur within this Russian invention system. Parts 2 and 3 gaves the first 26 common principles that are used in many patents. Part 4 now completes this list. Use these principles at any time during problem solving and inventing. Just go through them all and ask, ‘How can I use this to help solve my problem?’
27. Inexpensive short life
When something is relatively expensive or causes other problems, you might be able to replace it with something cheaper that works for the moment. This is a principle than has been used many times to create a disposable society. From Gillette’s razor blades onwards, many inventors have found that a lucrative income can be created with cheap devices that people buy regularly.
28. Replacement of a mechanical system
Mechanical inventors sometimes get trapped by their discipline and opportunities arise for those with knowledge of other subjects can improve the system. You can even replace physical systems with invisible effects, for example replacing wheels on a train by a magnetic lift system. You can also create different effects by varying fields such as using high frequencies or pulsing.
29. Use pneumatic or hydraulic systems
In its most general form, this principle is about replacing solids with liquids or gases, which can easily be channelled and have different properties such as their flexibility, which can be useful for cushioning. Pneumatic and hydraulic systems are particularly useful for channelling energy to a desired place, using flexible pipes. By changing the bore of the pipe, pressure can also be easily increased or decreased.
30. Flexible film or thin membranes
Thin films have a number of useful properties, such as low cost, low space, flexibility and usage. They can be used to separate, isolate and protect, such as the ‘cling film’ that is used to wrap food. The film can be bought in a roll, but it can also be created in situ (paint is just such a useful thin film).
31. Use of porous materials
Porous material allow some substances through them and block others, which allows them to be used for separating and filtering out desired or undesirable elements. As with mops, they also can be used for absorbing and collecting liquids or gases, which can subsequently be released in a controlled manner as required. Where porosity is an undesirable effect, then you may want to clog up the pores rather than utilise them.
32. Changing the colour
Colour can be an aesthetic factor or it can have practical uses, such as signalling danger. It can also be used as a detection mechanism, such as the use of litmus paper to determine acidity levels. You can also change the transparency of colours, such as in optical filters.
A homogeneous substance is made up of the same material. So what if you made your device out of different materials? What would be the effect of each part? How would these interact? What if you used all the same material? The principle of homogeneity can also be used in other areas, such as the behaviour of parts of the system. In an electronic system all plugs could be the same to reduce costs, or they could be different to prevent accidentally plugging things into the wrong place.
34. Rejecting and regenerating parts
When a part has been used and is no longer needed, what do you do with it? Typically you either throw it away, restore it or recycle it somehow. Whichever approach you use, you will probably need to include some system to cope with this.
35. Transforming physical or chemical states
Sometimes changing the object in some way, such as its temperature, concentration or density, is useful. Think of the chemical composition of the substances. What is the relationship between the atoms and molecules? Are they tightly bound together, do they slide around or come apart easily? Look at the effects on flexibility, load-bearing, chemical reactions, and so on.
36. Phase transition
Substances often go through changes, such as expanding, evaporating, cooling or changing shape. Think about how this happens and how you can start, stop or otherwise control the change. Is the effect reversible? Can you use a simple catalytic effect?
37. Thermal expansion
When you heat things up, they usually expand at varying rates. This can either be a problem that you need to handle or it can be a tool to solve problems. The bimetallic strip is a simple example where two connected metal strips, each of which expands at a different rate, resulting in a device which bends when it is heated, thus giving the basis of many thermostats and thermometers.
38. Use strong oxidisers
The oxygen in the air reacts with many substances, from iron (creating rust) to flammable substances (enabling fire). This effect can be increased by using materials which combine with oxygen more easily or by adding more oxygen to the system, for example in a blowtorch.
39. Inert environment
When oxygen and other reagents in the environment are a problem, sometimes a good solution is to take them away, replacing them with chemicals that will not react with your device. For example, light bulbs are partially evacuated and filled with inert gases to prevent the thin filament from oxidising and thus breaking.
40. Composite materials
When things are made of all the same substance, they are vulnerable to problems that affect that material. By using a combination of materials, synergistic effects can be created where the different materials used not only contribute their different properties, they also act together to provide something that is better than any individual part. For example, composite bows can fire arrows further and more consistently than bows made of any single material.
Next time: Attribute analysis
This article first appeared in Quality World, the journal of the Institute for Quality Assurance
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