You can imagine big cities where millions of people fill the sidewalk in the busy hours. It would be great if the power of walking could be transformed to electricity or heat and used in the nearby buildings. Some of the initial steps have been in made in this direction.
Piezoelectric effect could be used to generate the electricity from the vibrations that are created by walking. Considering the fact that there will be rapid improvements in this field, we could surely expect that the future sidewalks will be equipped with piezoelectric cells.
Thermal power could be generated by walking. This technology is already employed in Sweden. The vibrations that are caused by walking can power the heat pump and heat the nearby buildings.
Kinetic clothes and shoes will have increased popularity in the future. Specially designed shoes will be able to create electricity that could be used to charge mobile phones and other gadgets.
Self-cleaning sidewalks will be used to absorb the air pollution. Special titanium dioxide nano-particles could be incorporated in the sidewalks and absorb the dangerous gasses, particularly nitrogen oxides.
Source:
http://www.treehugger.com/clean-technology/six-sidewalks-that-work-while-you-walk.html