The invention provides a method for preparing a conductive strain sensor on the surface of a device to measure strain at the surface of the device, which method comprises the steps of: (a) providing a device; (b) optionally applying an isolating layer on a surface of the device; (c) establishing a distribution of particles of a first metal on the isolating layer obtained in step (b); and (d) depositing a layer of a second metal on at least part of the distribution of the particles of the first metal as obtained in step (c) by means of an electroless plating process or electro-deposition process.