Electronic paper could make these even lighter and changing or recharging batteries could become a thing of the past.

ECONOMIST: Showing off

It is not only electronic gadgets that have become smaller and lighter over the years even as their performance has improved but many other things too, from cars to plastic bags.

ECONOMIST: Less is more

Electronic steering was developed in part to provide a lighter, more compact form of power-steering for small cars and for hybrid vehicles, which require steering assistance when running on batteries alone.

ECONOMIST: Rational consumer