Because the electrolyte is very thin compared to the cantilever, the cantilever effectively prevents the electrolyte from straining perpendicular to the bar's axis. Thus, other strains within the plane of the bar's surface can be neglected, yielding a plane strain elastic problem. From Hooke's law, we can state the stress along the bar's axis (𝜎𝜎 𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎 ) as: