Figure 31 shows energy harvesting performance of the sensor of Figure 30; Figure 32 shows testing results for grid control patterns of the sensor of Figure 12 ; Figure 33 shows examples of flexible and stretchable sensors and signals generated thereby; Figure 34 shows test results during another process for optimising electrode spacing for a triboelectric sensor; Figure 35 shows an embodiment of a sensor with a grid configured according to L S coding, and signals generated during use thereof; Figure 36 is an illustration of the tolerance in variation in sliding speed for a sensor having a grid configured in accordance with 0/1 coding; Figure 37 shows the peak to peak time duration for signals generated by the sensor of Figure 12; Figure 38 shows application of a triboelectric sensor with a grid configured according to 0/1 coding as an interface for a calculator; and Figure 39 schematically depicts a process for fabricating a triboelectric sensor according to certain embodiments. DETAILED DESCRIPTION Embodiments of the present disclosure relate to a triboelectric sensor comprising: a substrate; at least one grid structure disposed in or on the substrate; and at least one electrode for collecting triboelectric charges generated by sliding of an object over a surface of the substrate. The at least one grid structure is configured such that motion of the object is detectable from