In a particular kind of electromagnetic space called a Rindler space, the Casimir effect is huge. The essential idea here is that the space can be designed to allow only certain wavelengths to operate. If the electromagnetic properties of the Rindler space are matched to the ambient temperature, then these kinds of thermal waves can be made to dominate the Casimir energy.
That makes the Casimir energy huge. Zhao and Miao calculate that in a lab at 300K (room temperature), the Casimir energy would be some 100 billion times bigger than the free space value. That’s a significant difference that ought to make these effects accessible in an entirely new way to a much broader audience.
Zhao and Miao also say that this kind of material ought to be relatively straightforward to build, layer by layer.