Stretchable microelectrode arrays (stretchable MEAs or sMEAs) (also referred to as stretchable multielectrode arrays) are a specialized type of microelectrode array (MEA) with a key advantage; they can be deformed, stretched, bent, and twisted while maintaining electrical functionality whereas standard MEAs break upon mechanical loading. Flexible MEAs (flexMEA), which are often confounded with stretchable MEAs, lie in between stretchable MEAs and standard MEA in terms of their mechanical properties because they bend and twist to some degree, but not stretch. Just like traditional MEAs, stretchable MEAs consist of a few thousand microelectrodes that allow recording or stimulation of electrical signals from cells (neurons, muscles, etc.), and are used in vivo in a living being or in vitro with cell cultures.