Adding Thickness to FE-IBM

In the original Immersed Boundary Method, the solid is usually considered thin, or of codimension one. Thickness could be achieved by stacking together several one-dimensional fibers (like in the first movie below). A more general solution, based on Hyper-Elastic theory and standard variational principles was proposed in the reference below. This solution is still suboptimal, in the sense that the solid is still required to be incompressible and viscous, with the same viscosity type of the surrounding fluid.