This microscopic pyramid is actually a cage for a living cell, constructed to better observe cells in their natural 3D environment, as opposed to the usual flat plane of a Petri dish.
Researchers from the University of Twente in the Netherlands made the cage by depositing nitrides over silicon pits. When most of the material is peeled away, a small amount of material remains in the corners to create a pyramid.
Because the pyramids have holes in the sides and are close together, the cells can interact for the most part as they naturally do. "The thing is because they're so open, cells can easily make connections to the outside," said Aart van Apeldoorn, one of the researchers. "The 3D surface is more or less mimicking how cells act in actual tissues. Everything in our body is three-dimensional."