An ultra-thin, stretchable, and transparent hydrogenbonded poly(ethylene oxide) and poly(acrylic acid) ([PEO/PAA] n ) bilayer (BL) positive triboelectric film was developed using a low-cost and eco-friendly layer-by-layer method. [PEO/PAA] n films exhibited remarkable output performance, enabling designability, foldability, and sustainability for versatile application of triboelectric nanogenerators (TENGs). The dependence of TENG behaviors on thickness was investigated by varying the number of BLs in [PEO/PAA] n films. It was demonstrated that a 1.6-μm-thick [PEO/PAA] 20 TENG resulted in an optimal electrical output performance of 303 V and 36.1 mA m −2 , owing to a higher affinity for electron donation and the lowest work function. A free-standing (FS) skin-like [PEO/PAA] 100 TENG was designed for shape-adaptive kirigami-type nanogenerators, exhibiting ∼100% ultrahigh transparency, ∼900% super-stretchability, and extraordinary foldability to 1/32 its original size. Thus, FS-TENG could be attached to the skin, a wall, or the insole of a shoe, showing an output of 321, 501, and 319 V, respectively, enough to simultaneously turn on 39 green LEDs by manually tapping or running.
A mechanosensitive, visco‐poroelastic polymer ion pump that can rapidly establish a dense electrical double layer via mechanical pressure, thereby significantly enhancing output performance of an ionic triboelectric nanogenerator (iTENG), is described. A working mechanism of an iTENG using a highly mechanosensitive, visco‐poroelastic ion pump is suggested and the optimal characteristics of the polymer ion pump are reported by investigating optical, mechanical, electrical, and electrochemical properties. Surprisingly, the pressure sensitivity of the iTENG reaches 23.3 V kPa−1, which is tens of times the record value. To achieve controlled high‐frequency pulses from an iTENG, kinematic systems using a gear train and a cam are integrated with a single grounded iTENG, which produces a maximum of 600 V and 22 mA (≈2.2 W cm−2) at an input frequency of 1.67 Hz; after power transforming, those values are converted to 1.42 V and 225 mA. A capacitor of 1 mF can be fully charged to 2 V in only 60 s, making it possible to continuously operate a wireless‐communicating self‐powered humidity sensor. Also, due to the high transparency and deformability of the polymer ion pump, a self‐powered transparent tactile sensor is successfully assembled using a 5 × 5 iTENG array.
Triboelectric nanogenerators (TENGs) are used as self-power sources for various types of devices by converting external waves, wind, or other mechanical energies into electric power. However, obtaining a high-output performance is still of major concern for many applications. In this study, to enhance the output performance of polydimethylsiloxane (PDMS)-based TENGs, highly dielectric TiO2−x nanoparticles (NPs) were embedded as a function of weight ratio. TiO2−x NPs embedded in PDMS at 5% showed the highest output voltage and current. The improved output performance at 5% is strongly related to the change of oxygen vacancies on the PDMS surface, as well as the increased dielectric constant. Specifically, oxygen vacancies in the oxide nanoparticles are electrically positive charges, which is an important factor that can contribute to the exchange and trapping of electrons when driving a TENG. However, in TiO2−x NPs containing over 5%, the output performance was significantly degraded because of the increased leakage characteristics of the PDMS layer due to TiO2−x NPs aggregation, which formed an electron path.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.