Evolution of the ratio ν
2 with consecutive Co deposition times. (a) Evolution of the ratio ν2
2 with a consecutive deposition time of 1.0 min. This ratio for the CPA-MCL (featuring transverse nano-strings) has a slope that is practically equal to its initial slope and is consistent with the increment in mass of the C-MCL. This slope for the coated CPE-MCL (longitudinal nano-strings) is smaller than the slope for the CPA-MCL: an increase in the value of its spring constant, k
o, must have occurred because the increase in mass was the same for the two MCLs. (b) The same behaviour was observed for the other two simultaneously off-normal Co-coated micro-cantilevers with consecutive deposition times of 4.0 min.