This research has shown for the first time that the physical dimensions of small surface patterns in an object surface are detectable from sensors integrated into the fingertip and mechanical links of a prosthetic hand. A further novel aspect of this work is the use of the standard deviation of data used in the analysis. Charge amplifiers are used to extract the signal from the piezoelectric sensors when an object that has two grating surfaces moves past a fingertip. Similar signals have been observed from all the sensors. An analysis of the data has shown that the repeating pattern from the gratings is detectable from a calculation of the mean standard deviation. An estimate of the grating widths can also be made from this analysis. Approximately 32 and 58 grooves are in contact with fingertip (width 15mm) representing a resolution of 2 grooves and 4 grooves mm-1 respectively.