We demonstrate a practical and efficient hybrid triboelectric-piezoelectric energy harvesting structure that consists of a nanopatterned and/or metal-deposited polymer film and a piezoelectric elastomeric sponge. When a polymer (here, polycarbonate (PC)) and an elastomer (here, polydimethylsiloxane (PDMS)) make contact with and detach from each other, triboelectric energy can be harvested. In this case, the PC surface can be nanopatterned by continuous dynamic nanoinscribing and/or coated by a metal (here, Cu) layer for enhanced performance. When a piezoelectric material (here, lead zirconate titanate (PZT)) and sugar powder are mixed with PDMS, and the sugar is later dissolved, a porous piezoelectric elastomeric sponge (PES) can be fabricated. When a PC film and a PES make contact with and detach from each other, both triboelectric and piezoelectric energies can be simultaneously harvested. We systematically study the effect of PES and Cu thicknesses and dynamic nanoinscribed nanopattern on the energy harvesting performance of the hybrid triboelectric–piezoelectric nanogenerator (HTPENG). The performance of the HTPENG can be improved by using the PES of optimal thickness, and by applying the nanopattern and Cu layer. The HTPENG can be utilized in many systems where wireless self-powering is desired, such as wearable devices, flexible sensors, and skin electronics.

Fabrication of a durable and strong nanopatterned mold insert using metal sheet and plate is important for molding of thermoplastic materials. Conventionally, the nickel stamper replicating a master pattern by electroforming process has been used for injection molding of nanotextured products such as Blu-ray media. However, a more facile and cheaper mold fabrication process is highly required for manufacturing of functional products based on nanostructured surface. In this study, zirconia nanoparticles were blended with UV curing polymer to fabricate a polymer nanocompositebased nanopattern mold. Compared to the cured pure Ormostamp, the modulus of elasticity of the nanocomposite filled with approximately 54 vol% of zirconia nanoparticles increased by 160 times. Additionally, the modulus of elasticity reached 197 ㎬ by thermal decomposition of the UV-Cured polymer and post-annealing at 800°C of the nanoparticle layer. The nanopatterns were formed on stainless steel sheet and block, and applied to hot embossing of the PMMA films and injection molding of the COC materials, respectively. No deterioration of the mold occurred during the hot embossing 30 times and the injection molding 600 shots. Nanoparticle-enhanced UV curing nanocomposites or post-heat treatment methods are cost-efficient and easy, because many molds can be manufactured from one master pattern.