Final answer:
An ultramicrotome is the device used to slice thin sections for transmission electron microscopy, allowing for the high-resolution visualization of tissue sections and subcellular structures.
Step-by-step explanation:
The name of the device that is used to slice sections for transmission electron microscopy (TEM) is an ultramicrotome.
This device is capable of cutting extremely thin sections of a specimen, which are required to be thin enough for electrons to pass through when using a TEM.
The sections prepared by an ultramicrotome can then be examined under the TEM to visualize small, thin specimens such as tissue sections and subcellular structures with a high level of detail, potentially down to individual atoms.