Buckling of thin layers or aligned arrays of stiff materials on elastomeric substrates has many important applications, such as stretchable electronics, precision metrology and flexible optoelectronics. These systems show one common phenomenon, the stiff thin layers buckle normal to the substrate surface (out-of-surface buckling). By contrast, we recently reported for the first time that silicon nanowires (SiNWs) on elastomeric substrates buckle only within the substrate surface, i.e. in-surface buckling. Experimental process to obtain buckled SiNWs is described.