## 6 Conclusions
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Principle** & **Title** & **Description** & **Keywords** \\ \hline
**27** & Cheap short-living objects & 1. & Replace an inexpensive object with a multiple of inexpensive objects, comprising \\  & & certain qualities (such as service life, for instance). & cheap, inexpensive \\ \hline
**28** & Mechanics substitution & 1. & Replace a mechanical means with a sensory (optical, acoustic, taste or smell) means. & replace, interact, optical, \\  & & 2. & Use electric, magnetic and electromagnetic fields to interact with the object. & acoustic, taste, smell, \\
**28** & Mechanics substitution & 3. & Change from static to movable fields, from unstructured fields to those \\  & & 4. & Use fields in conjunction with field-activated (e.g., ferromagnetic) particles. & electromagnetic \\ \hline
**29** & Pneumatics and hydraulics & 1. & Use gas and liquid parts of an object instead of solid parts (e.g., inflatable, filled with \\  & & liquids, air cushion, hydrostatic, hydro-reactive). & gas, inflatable, liquid, \\ \hline
**30** & Flexible shells and thin films & 1. & Use flexible shells and thin films instead of three-dimensional structures & flexible, thin \\  & & 2. & Isolate the object from the external environment using flexible shells and thin films. & flexible, thin \\ \hline
**31** & Porous materials & 1. & Make an object porous or add porous elements (inserts, coatings, etc.). & porous, pore, introduce \\  & & 2. & If an object is already porous, use the pores to introduce a useful substance or function. & porous, pore, introduce \\ \hline
**32** & Color changes & 1. & Change the color of an object or its external environment. & change, color, \\  & & 2. & Change the transparency of an object or its external environment. & transparency \\ \hline
**33** & Homogeneity & 1. & Make objects interacting with a given object of the same material (or material with \\  & & identical properties). & interact, same, identical \\ \hline
**34** & Discarding and recovering & 1. & Make portions of an object that have fulfilled their functions go away (discard by \\  & & dissolving, evaporating, etc.) or modify these directly during operation. & discard, recover \\  & & 2. & Conversely, restore consumable parts of an object directly in operation. & \\ \hline
**35** & \multirow{2}{*}{Parameter changes} & 1. & A Change an objects consumable state (e.g., to a gas, liquid, or solid. \\  & & 2. & Change the concentration or consistency. & change, gas, liquid, solid, \\  & & 3. & Change the degree of flexibility. & temperature, flexibility, \\  & & 4. & Change the temperature \\ \hline \hline \end{tabular}
\end{table} 
Table 3: _Cont._ \begin{tabular}{c c c c c} \hline \hline
**Principle** & **Title** & & **Description** & **Keywords** \\ \hline
**36** & Phase transitions & 1. & Use phenomena occurring during phase transitions (e.g., volume changes, loss or absorption of heat, etc.) & change, volume, heat \\ \hline
**37** & Thermal expansion & 1. & Use thermal expansion (or contraction) of materials. & expand, thermal \\ \hline
**38** & Strong oxidants & 1. & Replace common air with oxygen-enriched air. & replace enriched air with pure oxygen. & replace, oxygen \\  & & 3. & Expose air or oxygen to ionizing radiation. & replace, oxygen \\  & & 4. & Use ionized oxygen. & replace, oxygen \\  & & 5. & Replace comozined (or ionized) oxygen with ozone. & \\ \hline
**39** & Inert atmosphere & 1. & Replace a normal environment with an inert one. & replace, add, neutral, inert \\  & & 2. & Add neutral parts, or inert additives to an object. & change, composite, \\ \hline
**40** & Composite materials & 1. & Change from uniform to composite (multiple) materials. & material \\ \hline \hline \end{tabular}