With the new-age technologies and cutting-edge composite materials etc available currently, is it possible that biplane and triplane designs will make a comeback in the near future?
Biplanes (and triplanes) became (nearly) extinct not because high strength materials (like composites) were not available, but because they became available.
One of the major reasons for use of biplanes in the early days of aviation was that the materials available were of insufficient strength for the (wing) designs used.
The major disadvantage of biplanes (or triplanes) is aerodynamic- it produces a lot of drag compared to the monoplane and the wings interfere with each other.
So, the biplane was an (aerodynamically) inefficient solution to a structural problem. As higher strength materials like Aluminum became widespread, the biplanes fell out of favor.
While they can be revived, I don't see why someone would do that, except for nostalgia (or some special uses, like aerobatics).
Biplanes were the best way to take to the air in the early days because people had not wrapped their minds around the concept of a thick wing. All early aircraft used very thin airfoils, and a biplane produced a very lightweight and strong wing. Materials, by the way, had nothing to do with this, so the use of modern composite materials will not change the situation.
But a biplane does have advantages: If you
- want the fastest possible roll rate,
- a compact airframe,
- want to fly slowly,
- have little need for payload,
a biplane will be the right solution. However, as soon as the plane is used to earn revenue by transporting goods or people quickly and efficiently over long distances, the monoplane is by far the better solution.
Contraptions like the Blériot type 67 will never be built again (except maybe for entertainment).
Blériot type 67 bomber (picture source). Note the very thin wing airfoils.
On the other hand, for flying fun an EAA Biplane is hard to beat. And it is super easy to build.
EAA Biplane P2 (picture source). This design is possible with any aviation-rated materials.
- The most efficient way to increase an aircraft's efficiency at converting thrust to lift is by increasing the amount of air that it is able to use. That's increasing the wingspan.
- It's less efficient to try to get more lift out of air that we are already using -- that's high-lift devices and stacked wings.
The increase in materials is what allowed us to get away from less-efficient methods like biplanes.
On the other hand, a particular wingspan constraint can drive development of multi-planes, as in aerobatics, where the violent forces are betetr resisted by shorter wings.
So perhaps there will continue to be niche applications, but I do not see any economical driver for multi-plane designs, and economics is what makes planes fly in any quantity.