Well, here’s one effort:
Significance: Around 100 y ago, Szilard imagined how to raise a weight without doing any work, just using the information gained by “looking” at a single gas molecule bouncing inside a box. Here, we designed an engine that stores energy by raising a bead against gravity, driven purely by information about the bead position. No work is done directly on the bead; instead, all dissipation occurs in the measuring apparatus. By choosing the right size of bead and through careful design, we improved information-engine performance by more than a factor of 10 over the best previous designs. We achieve a maximum velocity of 190 μm/s and maximum power of 103 kBT/s, numbers comparable to those measured in microorganisms.
The information engine designed by SFU researchers consists of a microscopic particle immersed in water and attached to a spring which, itself, is fixed to a movable stage.
Researchers then observe the particle bouncing up and down due to thermal motion.
“When we see an upward bounce, we move the stage up in response,” explains lead author and PhD student Tushar Saha. “When we see a downward bounce, we wait. This ends up lifting the entire system using only information about the particle’s position.”
Repeating this procedure, they raise the particle “a great height, and thus store a significant amount of gravitational energy,” without having to directly pull on the particle.
Saha further explains that, “in the lab, we implement this engine with an instrument known as an optical trap, which uses a laser to create a force on the particle that mimics that of the spring and stage.”
Joseph Lucero, a Master of Science student adds, “in our theoretical analysis, we find an interesting trade-off between the particle mass and the average time for the particle to bounce up. While heavier particles can store more gravitational energy, they generally also take longer to move up.”
“Guided by this insight, we picked the particle mass and other engine properties to maximize how fast the engine extracts energy, outperforming previous designs and achieving power comparable to molecular machinery in living cells, and speeds comparable to fast-swimming bacteria,” says postdoctoral fellowJannik Ehrich. University Communications, “World’s fastest information-fuelled engine designed by SFU researchers” at Simon Fraser University (May 11, 2021) The paper is closed access.
Hat tip: Philip Cunningham