Designable Skin-like Triboelectric Nanogenerators Using Layer-by-Layer Self-Assembled Polymeric Nanocomposites

Abstract

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.

Kirigami‐Inspired Biodesign for Applications in Healthcare

“…Staggered linear and Y-shape cuts (15 mm and 5 mm) [60] Photoactive silk fibroin Photolithography Staggered linear cuts (25 µm), branched Y-shape cuts, saddles, chevrons [37] Graphite electrodes on polyimide sheet Laser cutting Staggered linear cuts (over 3 cm) [61] Gold nanofilms Dual-beam focused ion beam (FIB)/SEM Arcs and 3D microdomes (sub-50-nm) [27] Gold traces embedded in thin-film Parylene C Oxygen plasma etching Serpentine cuts [62] Mono-layer MoS 2 on PDMS Molding and plasma etching Linear patterns, pyramids, out-of-plane springs with alternating C-shapes [35] PMMA-PI composite Wet etching and laser cutting 2D hierarchical designs [63] PEO-PAA composite Blade cutting Curved patterns, linear cuts [64] Multiwalled boron nitride nanotubes Pressure-induced Folded nanoribbon internal structures/pleats [65] PLA-PEDOT:PSS Laser cutting Y-shape cuts [24] Hydrogel films-carboxyl-Zr 4+ metal coordination complexes Photolithography Custom papercut designs, woven-like alternating vertical/horizontal lines [30] Graphene sandwiched between polyimide sheets Photolithography and reactive ion etching Mesh (islands connected by kirigami bridges) [66] Liquid crystal elastomer Two-photon polymerization (2PP) Linear cuts, hinged squares, [67] PET encapsulated in PDMS Laser cutting Graded kirigami (10 mm segments of increasing void area) [68] PVDF-TrFE composite (ZnO nanoparticles and MWCNTs)…”

“…Further, several light-emitting diodes (LEDs) could be illuminated through biomechanical motions such as, touching and running. [64] Other forms of energy storage devices for bio-applications include a kirigami inspired polypyrrole (PPy)/PEDOT composite film that could be used as a humidity dosimeter and stretchable supercapacitor. [104] Here, a rust-based vapor phase polymerization technique allowed in situ generation of homogeneous and high packing density nanofiber coatings on the electrode, resulting in an energy density of 115 µW h cm −2 at 1 mA cm −2 , and a stable stretch cycle capacitance after 300 stretching cycles.…”

“…Further, several light‐emitting diodes (LEDs) could be illuminated through biomechanical motions such as, touching and running. [ 64 ]…”

Recent Advances in Self-Powered Piezoelectric and Triboelectric Sensors: From Material and Structure Design to Frontier Applications of Artificial Intelligence

“…In addition, a polymer matrix with a kirigami structure can enhance the stretchability of a TENG. A self-powered stretchable wearable photodetector was developed using a kirigami-based honeycomb structure of zinc oxide nanowires and coupled with a TENG [125]. Embedding this device into a PDMS substrate with a kirigami pattern of honeycomb geometry showed outstanding stretchability with strains up to 125% (Figure 9c).…”

Layer-by-Layer Self-Assembled Thin Films for Triboelectric Energy Harvesting under Harsh Conditions

“…Overall, material choice is a vital variable for high performance TENG devices. Still, although not restricted to a specific material for the TENG device, , the tribomaterial (TM) should be paired with a large difference in triboelectric polarity. , However, less attention has been offered to the fabrication of positive TMs relative to negative TMs since the positive TMs are essential as the negative TMs, making their development necessary …”