Electronic devices are most practical as solid objects. Even batteries have moved from liquid based cells to solid-state forms such as lithium ion batteries. To understand how these function, the arrangement of the atoms and molecules needs to be understood. For example, in a lithium ion battery, the lithium ions have to be able to flow through the material; crystallography can be used to help understand the way that this process works. Over recent years, data storage has been possible on smaller and smaller units which are also lighter so that things like mobile phones are now essentially mini-computers. We have moved on from kilobytes of data on a USB data storage stick to gigabytes in the same volume (or even smaller) of object! It is an understanding of how the atoms and molecules are arranged that enables better data storage materials to be designed.
The electronics industry has grown up around the use of silicon; in this case, slices of single crystals of silicon are used, cut in a specific way related to the crystal structure.
Single crystals of quartz are used in the mechanism of watches to ensure that they keep good time.