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Graphene‐based epidermal dry electrodes have generated wide interests in electrocardiography (ECG) monitoring to screen cardiovascular diseases in time. Nevertheless, the poor stability, mechanical strength, and integration are significant obstacles hindering further product marketing of graphene electrodes in health care. Herein, robust, reusable, and patterned graphene‐based wearable dry electrodes are fabricated based on laser writing technology and supported by polydimethylsiloxane (PDMS) layers. After bending tests over 10 000 cycles and high‐power ultrasonic treatments (5 h), graphene/PDMS electrodes are demonstrated to have excellent stability and reusability for ECG recording. Taking the advantages of the designable and efficient CO2 laser production technique, a “staff‐shape” graphene electrode consisting of six chest‐lead electrodes and corresponding lead lines can be facilely customized and fabricated according to users’ somatotype to greatly simplify the acquisition procedure of 12‐lead ECG, realizing the acquisition of V1–V6 ECGs for all‐round cardiac monitoring. After thorough analysis of ECG patterns, the integrated chest electrode exhibits desirable sensitivity and reliability comparable to wet Ag/AgCl electrodes. The reusable graphene/PDMS electrodes are suitable for long‐term ECG monitoring and the integrated electrode presents a novel strategy to wearable 12‐ECG recording.

Abstract：In this paper, a mismatched filter bank is designed for suppressing the autocorrelation peak sidelobe level (PSL) and the peak cross-correlation level (PCCL) of an orthogonal polyphase sequence set applied in a multiple-input multiple-output (MIMO) radar system. The mismatched filter bank is obtained by minimizing a weighted maximum of the PSL and PCCL on the basis of the convex optimization. Compared with the iteratively reweighted least squares (IRLS) method, the proposed convex method can get the optimal mismatched filter bank with the minimum PSL and PCCL, and can also control the system signal-to-noise ratio loss (SNRL). Numerical examples show that the optimal mismatched filter bank at the cost of a slight SNRL can achieve a good improvement of the PSL and a moderate improvement of the PCCL, if the filter length P and the weighting factor w between the PSL and PCCL are appropriately chosen. Keywords：Mismatched filter bank design; orthogonal polyphase sequence set; multiple-input multiple-output (MIMO) radar; convex optimization

High-performance photovoltaic polymers bearing cross-linkable function together with a photorobust conjugated backbone are highly desirable for organic solar cells to achieve both high device efficiency and long-term stability. In this study, a family of such polymers is reported based on poly [(2,5-bis(2-hexyldecyloxy)), a high-performance photovoltaic donor− acceptor polymer, with different contents of terminal vinylappended side chains for cross-linking. The polymers were named PPDT2FBT-V x and prepared by varying the feeding ratio (x mol %, x = 0, 5, 10, and 15) of the vinyl-appended monomer in polymerization. It was found that the vinyl integration did not sacrifice the original high photovoltaic performance of the polymers, as evidenced by comparable average power conversion efficiencies (PCEs) (6.95, 7.02, and 7.63%) observed for optimized devices based on PPDT2FBT-V 0 , PPDT2FBT-V 5 , and PPDT2FBT-V 10 , respectively, in blending with [6,6]-phenyl-C 71 -butyric acid methyl ester (PC 71 BM). Unlike thermal cross-linking that greatly reduced device efficiency, UV cross-linking has proven to be an effective way to achieve both high device efficiency and thermostability for PPDT2FBT-V 10 solar cells. UV-cross-linked PPDT2FBT-V 10 solar cells displayed an initial average PCE of 5.28% and almost no decrease upon heat treatment at 120 °C for 40 h. Morphology studies revealed that UV-cross-linking did not only alter initial nanophase separation but also suppressed morphology evolution by aggregation in bulk heterojunction blend films. Photo-cross-linking requires material photostability. It is therefore worthwhile to note that these polymers and their blends with PC 71 BM were found to be extremely photostable, even upon continuous exposure to concentrated sunlight (up to 200 suns), and UV-cross-linking does not hamper this photostability. Further studies found that the devices fabricated with the UV-cross-linked PPDT2FBT-V 10 /PC 71 BM active layer can endure continuous light exposure to a solar simulator without deteriorating their performance.