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The vast proliferation of wearables and smart sensing devices in the last decade has created an immense demand for new and efficient powering solutions. The research focus has shifted towards developing simple, cost-effective, flexible device topologies capable of capturing kinetic energy associated with the human body. Piezoelectric and Triboelectric mechanisms are widely employed to convert biomechanical energy to electrical power due to their inherent merits in terms of affordable designs and high energy conversion efficiencies. In this work, we propose a flexible hybrid generator topology incorporating both piezoelectric and triboelectric mechanisms to achieve high electrical output from human motion. To enhance the efficiency and obtain a symmetric output, dual triboelectric generators are employed, which generate time-multiplexed output across the same set of electrodes. The device displays a characteristic ability to distinguish between different body movements as its output depends on the contact area as well as the pressure generated by the motion. This creates numerous avenues for employing the device in self-powered tactile sensing applications. The unique single substrate design makes the device robust and increases its longevity. The V-shaped prototype having an active area of 3.5 cm × 2 cm, is tested under a wide range of biomechanical stimuli, including touching, tapping, and pressing motions. The practical applications of the proposed device as an add-on patch on fabrics, as an in-sole device, and for powering commercial electronics are demonstrated. Apart from this, the reported generator can also fuel low-power devices from various other day-to-day human activities.

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Low-frequency (LF) magnetoelectric (ME) antennas are of great importance in implantable medical device (IMD) applications compared to their electromagnetic (EM) counterparts as they can potentially offer appropriate size miniaturization and lower path loss and higher efficiency. In this work, a self-biased, miniaturized LF ME antenna is proposed, which operates at its electromechanical resonant frequency of 49.9 kHz, with the size scaled down to only 1.75 mm3, which is significantly smaller than that of a comparable EM antenna. The proposed antenna that constitutes of a piezoelectric layer sandwiched between two magnetostrictive layers is characterized in both air and an optimized three-layered human tissue-mimicking phantom media to demonstrate the potential applications in deep-body communications. The near field radiation pattern of the ME antenna is measured experimentally. The maximum received power obtained at a distance of 1.2 m in air and phantom media is 20 and 8 nW, respectively. The proposed antenna has significantly lower path loss of 0.57 dB/m as compared to its higher frequency counterparts. Due to the lower path loss and smaller size, the proposed ME antenna can be suitable in several miniaturized IMD applications.

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