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Piezoelectric nanogenerators (PENGs) and triboelectric nanogenerators (TENGs) are representative technologies that can harvest mechanical energy. In general, piezoelectric/triboelectric hybrid generators can harvest considerable energy with a limited input; however, PENGs and TENGs entail different requirements for harvesting energy. Specifically, PENGs produce a large output when a large mechanical strain is applied, and TENGs require a large surface area to produce a high power. Therefore, it is necessary to develop an innovative strategy in terms of the structural design to satisfy the requirements of both PENGs and TENGs. In this study, we developed a triangulated cylinder origami-based piezoelectric/triboelectric hybrid generator (TCO-HG) with an origami structure to enable effective energy harvesting. The proposed structure consists of a vertical contact-separation TENG on the surface of the triangulated cylinder, PENG on the inner hinge, and rotational TENG on the top substrate to harvest mechanical energy from each motion. Each generator could produce a separate electrical output with a single input. The TCO-HG could charge a 22 μF commercial capacitor and power 60 LEDs when operated.

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With rapid urbanization and global population growth, the amount of wasted aluminum foil is significantly increasing. Most deformed and contaminated foil is difficult to recycle; hence, it is landfilled or incinerated, causing environmental pollution. Therefore, using aluminum foil waste for electricity may be conducive to addressing environmental problems. In this regard, various literatures have explored the concept of energy generation using foil, while a crumple ball design for this purpose has not been studied. Thus, a recycled foil‐based crumpled ball triboelectric nanogenerator (RFCB‐TENG) is proposed. The crumpled ball design can minimize the effects of contamination on foil, ensuring efficient power output. Moreover, owing to novel crumpled design, the RFCB‐TENG has some outstanding characteristics to become a sustainable power source, such as ultralight weight, low noise, and high durability. By introducing the air‐breakdown model, the RFCB‐TENG achieved an output peak voltage of 648 V, a current of 8.1 mA cm3, and an optimum power of 162.7 mW cm3. The structure of the RFCB‐TENG is systemically optimized depending on the design parameters to realize the optimum output performance. Finally, the RFCB‐TENG operated 500 LEDs and 30‐W commercial lamps. This work paves the guideline for effectively fabricating the TENG using waste‐materials while exhibiting outstanding characteristics.

As a valuable tool for harvesting energy, triboelectric nanogenerators (TENGs) exhibit notable advantages over other energy‐harvesting methods in terms of their low weight, low cost and high‐power density. Despite their application potential in the domain of portable electronics, TENGs exhibit a limited maximum output owing to the high surface charge density during operation. Furthermore, TENGs inherently produce alternative current (AC); thus, an additional electrical circuit such as a rectifying circuit must be used as a portable power source. To overcome these problems, a triboelectric generation mechanism that can produce both AC and direct current outputs with amplified electrical current through the addition of a simple mechanical component is established. The proposed pillar‐type TENG (P‐TENG) can minimize the electrical loss during operation that occurs due to the contact between electrodes, allowing electrons to flow directly. Moreover, a miniaturized and portable variant of the P‐TENG is designed to harvest mechanical energy in daily‐life activities.