A bimetallic strip used as a MEMS sensor is shown in Figure P2.12. The strip, has a length of \(20 \mu \mathrm{m}\). The width of the strip is \(1 \mu \mathrm{m}\). It has an upper layer made of steel (E \(52103109 \mathrm{~N} / \mathrm{m} 2\) ) and a lower layer made of aluminum (E 5 \(803109 \mathrm{~N} / \mathrm{m} 2)\). Each layer is \(0.1 \mu \mathrm{m}\) thick. Determine the equivalent stiffness of the strip in the axial direction.

1 FIGURE P 2.121 20 m Each layer is X 0.2 m 0.1 m thick