Science/Fiction

To mimic this architectural complexity in their engineered tissues, the researchers embedded a mixture of brain cells taken from the primary cortex of rats into sheets of hydrogel. They also included components of the extracellular matrix, which provides structural support and helps regulate cell behavior.

Those sheets were then stacked in layers, which can be sealed together using light to crosslink hydrogels. By covering layers of gels with plastic photomasks of varying shapes, the researchers could control how much of the gel was exposed to light, thus controlling the 3-D shape of the multilayer tissue construct. 

'Precisely Engineering 3-D Brain Tissues', MIT News (2012)
 

"This brain isn't frozen," said Tiga-belas indignantly. "It's been laminated. We stiffened it with celluprime and then we veneered it down, about seven thousand layers. Each one has plastic of at least two molecules thickness. This mouse can't spoil. As a matter of fact, this mouse is going to keep on thinking forever. He won't think much, unless we put the voltage on him, but he'll think. And he can't spoil..."

 'Think Blue, Count Two', Cordwainer Smith (1963)