Binary stiffness compliant mechanism measurement

Time-lapse video of a measurement of a fully compliant mechanism with binary stiffness. More details can be found in the research paper that is found at

EDIT: The research paper is now open access and can be freely downloaded by anyone at the doi link above.

[gownerjones]

I love compliant engineering. For anyone coming across this and wondering what you're looking at, this is a compliant mechanism. That means it's a mechanism that moves without moving parts. The movement is made possible but also constrained by the geometry of the part. In this example mechanism, a bistable switch on the right side of the mechanism is connected by two V-shaped blade flexures to the mechanism on the left. If the switch is pressed to the right, it snaps into one of its stable states when the v shaped flexures are perfectly straight, making up and down movement on the left side of the mechanism impossible. The left side mechanism now has effectively infinite stiffness and will resist up and down movement. When the bistable switch is toggled (this happens here by forcefully pulling on the left side mechanism), the two V-shaped flexures buckle and flex in such a way to create a spring force in the up and down directions that perfectly counteract the forces by the small flexures on the upper and lower side of the left side mechanism. By doing this, the left side mechsnism can now freely move up and down and because the forces cancel out on it, it effectively exists at 0 stiffness which allows it to move without resistance.

By combining these two elements, we now have a mechanism that can switch between 0 and infinite stiffness at the literal push of a button, all without any moving parts and without any electronics or sensors or anything like that. That's the beauty of compliant design.

[numoru]

Move the mechanism at different frequencies it'll set up resonant frequencies and will pop out, make those 3 on the right different weights/length then business

[kildozer]

And the result of the measurements were??

[pvic]

3k subs, 6k views, and only 3 comments?? lol

[kotsaris]

I don't know... Whenever i see compliant mechanisms, i see a cheap construction designed to fail