During my mid morning nap this came to me in a dream.

The chair has an inflatable cushion.

In each leg there is an air compressor.

Every time you sit down air is compressed and a small computer keeps the cushion on your desired firmness.
-- zeno, Mar 27 2009

Here's one... not quite what you want http://www.sportsun...ng-trail-chair.html
[21 Quest, Mar 27 2009]

Aha! Found it! http://furniture.ab.../p/pro_13109rec.htm
[21 Quest, Mar 27 2009]

Ahh, my desired firmness - how I miss her so.
-- zen_tom, Mar 27 2009


George thinks this would be an excellent feature for his inflatable doll.
-- vfrackis, Mar 27 2009


I think the chair should explosively inflate, like an air bag. It could be stored in the seat of one's pants. One would then deploy it as one prepared to sit in a previously chairless space.
-- bungston, Mar 27 2009


Uh... I've seen air-chamber chairs before... with adjustable settings. Some even have memory buttons.
-- 21 Quest, Mar 27 2009


where is the "firmness" going that it needs such constant refurbishment?
-- WcW, Mar 27 2009


Sorry, but I believe the following quote from my second link proves your idea is baked:

//The recliner has patented air chamber technology in the weight bearing areas. This allows users to adjust the firmness or softness of the cushions from 0 (very soft) to 9 (very firm). In addition to this, the air chamber technology allows for different levels of lumbar support to ease lower back pain or stiffness.//
-- 21 Quest, Mar 27 2009



halfbakery