Airlines are very sensitive to the costs of their operations, so reducing the weight of aircraft is important.
Today’s invention is therefore a hammock-like seat for airlines with a much smaller mass than a conventional seat.
This would be made of a netting bag with a fold-down seat unit built-in.
A passenger could carry this aboard themselves and attach it to a hook in the roof.
The attachment might include a spring/damper/hinge unit to limit the amount of motion during eg turbulence. There might also be an elasticated cord between seat and floor.
Such a design would also speed boarding and egress, since the seats are easy to move past, automatically reverting to a narrow rope shape when not in use.
Possibly also useful for armoured cars so that shocks from IEDs don’t pass through to the occupants.
Armoured cars are increasingly equipped with really clever seat mechanisms.
http://www.armorworks.com/news/detail/armorworks-receives-5-million-order-for-blast-attenuating-seats/
They can experience the same impact when a mine goes off as driving over a 100ft cliff.