Cellular construction with cells that are generally interconnected. Among RMT architectures, an open cell void array is one in which each void is connected to other voids. These cells cannot hold a gas. Gas moves freely within and throughout the entire cellular structure.

Foamed or cellular material with cells which are generally interconnected. Closed cells refers to cells which are not interconnected.

A cell not totally enclosed by its walls connecting with other cells. Non-isolated chambers. As opposed to ‘closed-cell.'