Triboelectrification on natural rose petal for harvesting environmental mechanical energy

Rose swayed in the breeze are responsible for harnessing the kinetic energy of wind. From a certain perspective, these phenomenon can be utilized to augment plant function to generate electricity with electroactive materials, where triboelectrification happens for producing electricity due to the difference in triboelectric polarity. In this paper, we creatively utilized the triboelectrification on plant organs, which has rarely been studied before, and constructed triboelectric nanogenerators (TENGs) by using rose and Poly (methyl methacrylate) in a contact-separation mode. Under a constant periodical compressive force (100 N) at a frequency of 2 Hz, a maximum open-circuit voltage (V-oc) of 30.6 V and short-circuit current (I-sc) of 0.78 mu A were obtained from a fresh rose petal (3 cm x 3 cm). The maximum output power density could be as high as 27.2 mW/m(2) at a resistance of 50 M Omega. Further studies disclosed that these petal surface rich in micro- and nanostructures provided sufficient roughness for hydrophobicity, which means that electrical charges could be generated and the mechanical energy of rain drops could be harvested. Therefore, I-sc generated from the petal with falling water droplets on its surface was measured and the peak of I-sc was 7.84 nA.