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Harvesting renewable mechanical energy is envisioned as a promising and sustainable way for power generation. Many recent mechanical energy harvesters are able to produce instantaneous (pulsed) electricity with a high peak voltage of over 100 V. However, directly storing such irregular high-voltage pulse electricity remains a great challenge. The use of extra power management components can boost storage efficiency but increase system complexity. Here utilizing the conducting polymer PEDOT:PSS, high-rate metal-free micro-supercapacitor (MSC) arrays are successfully fabricated for direct high-efficiency storage of high-voltage pulse electricity. Within an area of 2.4 × 3.4 cm2 on various paper substrates, large-scale MSC arrays (comprising up to 100 cells) can be printed to deliver a working voltage window of 160 V at an ultrahigh scan rate up to 30 V s−1. The ultrahigh rate capability enables the MSC arrays to quickly capture and efficiently store the high-voltage (≈150 V) pulse electricity produced by a droplet-based electricity generator at a high efficiency of 62%, significantly higher than that (<2%) of the batteries or capacitors demonstrated in the literature. Moreover, the compact and metal-free features make these MSC arrays excellent candidates for sustainable high-performance energy storage in self-charging power systems., QC 20231122

The rapid development of emerging electronics requires power sources with the advantages of lightweight, high efficiency, and portability. Considering the use of critical raw materials (such as Li, Co, etc.) and the increasing global concern of battery waste, self-charging power systems (SCPSs) integrating energy harvesting, power management, and energy storage devices have been envisioned as promising solutions to replace traditional batteries to avoid the use of toxic materials and the need of frequent recharging/replacement. Up to date, the reported SCPSs still hold the problem of large form factor, unscalable fabrication, noble materials, and material complexity. In our work, a highly stable and eco-friendly organic conductive ink based on poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) has been developed for monolithic fabrication on-paper SCPSs almost fully through a simple direct ink writing (DIW) process. The ink possesses multiple functions and enables to directly print almost all the key components in the SCPSs, including electrodes for triboelectric nanogenerators (TENGs, mechanical energy harvesters), electrodes for micro-supercapacitors (MSCs, energy storage devices), and interconnects, on the same paper substrate in a monolithic manner without the need for “post-integration”. The monolithic printing process exhibits excellent upscaling capability for manufacturing. In particular, the direct patterning merit of the DIW process offers great flexibility in optimizing the system performance through adjusting the cell number, electrode dimension, and thickness of the MSC arrays. By adjusting the cell numbers, the MSC arrays attain high-rate capability up to 50 V/s to match the pulsing electricity produced from the TENGs. For small-size printed SCPSs (~ 2 cm × 3 cm ×1 mm), after continuous press and release of the TENGs for ~79000 cycles, the 3-cell series-connected MSC array can be charged to 1.6 V while 6-cell array to 3.0 V. For a lar, Part of ISBN 9789189896925QC 20240719

Self-charging power systems (SCPSs) are envisioned as promising solutions for emerging electronics to mitigate the increasing global concern about battery waste. However, present SCPSs suffer from large form factors, unscalable fabrication, and material complexity. Herein, a type of highly stable, eco-friendly conductive inks based on poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) are developed for direct ink writing of multiple components in the SCPSs, including electrodes for miniaturized spacer-free triboelectric nanogenerators (TENGs) and microsupercapacitors (MSCs), and interconnects. The principle of “one ink, multiple functions” enables to almost fully print the entire SCPSs on the same paper substrate in a monolithic manner without post-integration. The monolithic fabrication significantly improves the upscaling capability for manufacturing and reduces the form factor of the entire SCPSs (a small footprint area of ≈2 cm × 3 cm and thickness of ≈1 mm). After pressing/releasing the TENGs for ≈79000 cycles, the 3-cell series-connected MSC array can be charged to 1.6 V while the 6-cell array to 3.0 V. On-paper SCPSs are promising to serve as lightweight, thin, sustainable, and low-cost power supplies., QC 20240514

The raised demand for portable electronics in high-temperature environments (> 150 degrees C) stimulates the search for solutions to release the temperature constraints of power supply. All-solid-state microsupercapacitors (MSCs) are envisioned as promising on-chip power supply components, but at present, nearly none of them can work at temperature over 200 degrees C, mainly restricted by the electrolytes which possess either low thermal stability or incompatible fabrication process with on-chip integration. In this work, we have developed a novel process to fabricate highly thermally stable ionic liquid/ceramic composite electrolytes for on-chip integrated MSCs. Remarkably, the electrolytes enable MSCs with graphene-based electrodes to operate at temperatures as high as 250 degrees C with a high areal capacitance (similar to 72 mFcm(-2) at 5 mVs(-1)) and good cycling stability (70% capacitance retention after 1000 cycles at 1.4 mAcm(-2)).

Ever-growing various applications, especially for tissue regeneration, cause a pressing need for novel methods to functionalize melt electrowritten (MEW) microfibrous scaffolds with unique nanomaterials. Here, two novel strategies are proposed to modify MEW polycaprolactone (PCL) grids with ZnO nanoparticles (ZP) or ZnO nanoflakes (ZF) to enhance osteogenic differentiation. The calcium mineralization levels of MC3T3 osteoblasts cultured on PCL/ZP 0.1 scaffolds are ∼3.91-fold higher than those cultured on nonmodified PCL scaffolds, respectively. Due to the nanotopography mimicking bone anatomy, the PCL/ZF scaffolds (∼2.60 times higher in ALP activity compared to PCL/ZP 1 and ∼2.17 times higher in mineralization compared to PCL/ZP 0.1) achieved superior results. Moreover, the flexible feature inherited from PCL grids makes it possible for them to act as a reshapable osteogenic bioscaffold. This study provides new strategies for synthesizing nanomaterials on microscale surfaces, opening up a new route for functionalizing MEW scaffolds to fulfill the growing demand of tissue engineering., QC 20220613