@article{son_lee_wang_samson_wei_zhu_you_2022, title={Integrating charge mobility, stability and stretchability within conjugated polymer films for stretchable multifunctional sensors}, volume={13}, ISSN={["2041-1723"]}, url={https://doi.org/10.1038/s41467-022-30361-0}, DOI={10.1038/s41467-022-30361-0}, abstractNote={Conjugated polymers (CPs) are promising semiconductors for intrinsically stretchable electronic devices. Ideally, such CPs should exhibit high charge mobility, excellent stability, and high stretchability. However, converging all these desirable properties in CPs has not been achieved via molecular design and/or device engineering. This work details the design, synthesis and characterization of a random polythiophene (RP-T50) containing ~50 mol% of thiophene units with a thermocleavable tertiary ester side chain and ~50 mol% of unsubstituted thiophene units, which, upon thermocleavage of alkyl chains, shows significant improvement of charge mobility and stability. Thermal annealing a RP-T50 film coated on a stretchable polydimethylsiloxane substrate spontaneously generates wrinkling in the polymer film, which effectively enhances the stretchability of the polymer film. The wrinkled RP-T50-based stretchable sensors can effectively detect humidity, ethanol, temperature and light even under 50% uniaxial and 30% biaxial strains. Our discoveries offer new design rationale of strategically applying CPs to intrinsically stretchable electronic systems.}, number={1}, journal={NATURE COMMUNICATIONS}, author={Son, Sung Yun and Lee, Giwon and Wang, Hongyu and Samson, Stephanie and Wei, Qingshan and Zhu, Yong and You, Wei}, year={2022}, month={May} }
 @article{liu_wang_zhu_2021, title={Recycling of Nanowire Percolation Network for Sustainable Soft Electronics}, ISSN={["2199-160X"]}, DOI={10.1002/aelm.202100588}, abstractNote={There is an increasing demand for eco-friendly and sustainable electronics, where recycling of functional materials is the key. Soft electronics have received much attention recently, however, their recycling has been challenging. Here a strategy is reported to recycle silver nanowire (AgNW) percolation network to achieve sustainable soft electronics. The effect of working solvent and ultrasonication time on the morphology and electrical properties of the recycled AgNW network is investigated. Using the selected working solvent with low surface tension (isopropanol) and optimal ultrasonication time (20 s), the AgNW network film can be recycled multiple times (four times in this work) without significant morphology changes and performance degradation. A transient epidermal sensor patch using AgNW as electrodes and a water-soluble polymer substrate is fabricated and fully recycled. On-body test of the epidermal sensor patch fabricated by recycled AgNWs demonstrates a working example for the recycling concept of AgNWs. The recycling concept can be extended to other nanomaterials in the form of percolation network.}, journal={ADVANCED ELECTRONIC MATERIALS}, author={Liu, Yuxuan and Wang, Hongyu and Zhu, Yong}, year={2021}, month={Jul} }
 @article{song_yao_liu_wang_dong_zhu_brendan t. o'connor_2020, title={Facile Approach to Fabricating Stretchable Organic Transistors with Laser-Patterned Ag Nanowire Electrodes}, volume={12}, ISSN={["1944-8252"]}, url={https://doi.org/10.1021/acsami.0c15339}, DOI={10.1021/acsami.0c15339}, abstractNote={Stretchable electronics are poised to revolutionize personal healthcare and robotics, where they enable distributed and conformal sensors. Transistors are fundamental building blocks of electronics, and there is a need to produce stretchable transistors using low-cost and scalable fabrication techniques. Here, we introduce a facile fabrication approach using laser patterning and transfer printing to achieve high-performance, solution-processed intrinsically stretchable organic thin-film transistors (OTFTs). The device consists of Ag nanowire (NW) electrodes, where the source and drain electrodes are patterned using laser ablation. The Ag NWs are then partially embedded in a poly(dimethylsiloxane) (PDMS) matrix. The electrodes are combined with a PDMS dielectric and polymer semiconductor, where the layers are individually transfer printed to complete the OTFT. Two polymer semiconductors, DPP-DTT and DPP-4T, are considered and show stable operation under the cyclic strain of 20 and 40%, respectively. The OTFTs maintain electrical performance by adopting a buckled structure after the first stretch-release cycle. The conformability and stretchability of the OTFT is also demonstrated by operating the transistor while adhered to a finger being flexed. The ability to pattern highly conductive Ag NW networks using laser ablation to pattern electrodes as well as interconnects provides a simple strategy to produce complex stretchable OTFT-based circuits.}, number={45}, journal={ACS APPLIED MATERIALS & INTERFACES}, publisher={American Chemical Society (ACS)}, author={Song, Runqiao and Yao, Shanshan and Liu, Yuxuan and Wang, Hongyu and Dong, Jingyan and Zhu, Yong and Brendan T. O'Connor}, year={2020}, month={Nov}, pages={50675–50683} }
 @article{zhou_yao_wang_du_ma_zhu_2020, title={Gas-Permeable, Ultrathin, Stretchable Epidermal Electronics with Porous Electrodes}, volume={14}, ISSN={["1936-086X"]}, DOI={10.1021/acsnano.0c00906}, abstractNote={We present gas-permeable, ultrathin, and stretchable electrodes enabled by self-assembled porous substrates and conductive nanostructures. An efficient and scalable breath figure method is employed to introduce the porous skeleton, and then silver nanowires (AgNWs) are dip-coated and heat-pressed to offer electric conductivity. The resulting film has a transmittance of 61%, sheet resistance of 7.3 Ω/sq, and water vapor permeability of 23 mg cm-2 h-1. With AgNWs embedded below the surface of the polymer, the electrode exhibits excellent stability in the presence of sweat and after long-term wear. We demonstrate the promising potential of the electrode for wearable electronics in two representative applications: skin-mountable biopotential sensing for healthcare and textile-integrated touch sensing for human-machine interfaces. The electrode can form conformal contact with human skin, leading to low skin-electrode impedance and high-quality biopotential signals. In addition, the textile electrode can be used in a self-capacitance wireless touch sensing system.}, number={5}, journal={ACS NANO}, author={Zhou, Weixin and Yao, Shanshan and Wang, Hongyu and Du, QIngchuan and Ma, Yanwen and Zhu, Yong}, year={2020}, month={May}, pages={5798–5805} }