Congratulations to Tianjun, Amin, and Melike on their new paper in Bioinspiration and Biomimetics! We have shown >50% propulsive efficiency for pitching 3D foils with tailored non-uniform flexibility. Check it out!
https://iopscience.iop.org/article/10.1088/1748-3190/ac7f70
Optimal foil: