Synthesis of large scale arrays of ZnO nanospikes with ultra sharp tips (<10 nm) is achieved through a newly developed chemical methodology. This is the first room temperature report of growing 1D ZnO nanostructures on heterogeneous substrates. The deposition was performed on various substrates including planar (silicon, conducting glass, copper foil), cylindrical (metallic wire) and flexible carbon cloth. The deposition technique is a universal one in the sense that it is compatible with complex shape substrates as well as independent of the nature of the substrate material. The arrangement of the nanospikes over the substrates may be altered from a dense array to a distributed flower like structure depending on the substrate pretreatment. The nanospikes exhibit excellent field emission performance caused by their emission beneficial geometry with turn-on and threshold fields showing significant dependence on the growth substrate. The turn-on field and the field enhancement factor are found to be the lowest and the highest for the ZnO deposited on carbon cloth substrates having values of 0.7 V μm⁻¹ and 2.6 × 10⁴ respectively. These are the best values compared to all reported chemically synthesized ZnO nanostructures and comparable to the best results of vapor phase deposited ZnO nanostructures. The synthesis method reported here will open-up a new door for future development of nano-based flexible electronics.

Mechano-electrical writing and reading in polyaniline (PANI) thin film are demonstrated via metal-polymer contact electrification mechanism (CEM). An innovative conception for a non-destructive self-powered writable-readable data sheet is presented which can pave the way towards new type of stress induced current harvesting devices. A localized forced deformation of the interface has been enacted by pressing the atomic force microscopic probe against the polymer surface, allowing charge transfer between materials interfaces. The process yields a well-defined charge pattern by transmuting mechanical stress in to readable information. The average of output current increment has been influenced from 0.5 nA to 15 nA for the applied force of 2 nN to 14 nN instead of electrical bias. These results underscore the importance of stress-induced current harvesting mechanism and could be scaled up for charge patterning of polymer surface to writable-readable data sheet. Time evolutional current distribution (TECD) study of the stress-induced patterned PANI surface shows the response of readability of the recorded data with time.