Wearable heaters have garnered significant attention from academia and industry for their great potential in thermotherapy. Silver nanowire (AgNW) is a promising conductive material for flexible and stretchable electrodes. Here, a resistive, biaxially stretchable heater based on AgNW composite is reported for the first time, where a AgNW percolation network is encased in a thin polyimide (PI) film and integrated with a highly stretchable textile. AgNW/PI is patterned with a 2D Kirigami structure, which enables constant resistance under a large tensile strain (up to uniaxial 100% strain and 50% biaxial strain). The heater can achieve a high temperature of ∼140 °C with a low current of 0.125 A, fast heating and cooling rates of ∼16.5 and ∼14.1 °C s–1, respectively, and stable performance over 400 heating cycles. A feedback control system is developed to provide constant heating temperature under a temperature change of the surrounding environment. Demonstrated applications in applying thermotherapy at the curvilinear surface of the knee using the stretchable heater illustrate its promising potential for wearable applications.

Capturing of digital images through Mobile based e-governance applications are growing day-by-day and issue related to protection of copyrights of digital images has become very critical. Protecting these high-volume geo-tagged time stamped digital images captured through android apps and ensuring that these images are suitable for social audit are key challenge for today’s application development. Digital image watermarking is a process by which secret information can be  in digital images so that it is possible to guard copyrights. The paper discusses an efficient digital image watermarking system using lifting wavelet transform. The proposed algorithm aims to minimize distortion of selected watermarked image. The performance of the algorithm has been tested using available images with MATLAB and their results have been properly analyzed with existing methods. The variance value between coefficients of lifting wavelet transform (LFT) in a block with size 2 x 2 has been chosen for embedding the binary watermark and the blocks are also then shuffled randomly. The result of various experiments has demonstrated that the developed algorithm is robust against various types of attacks being applied.

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