Many sensor applications require small and noninvasive methods of powering, such as marine animal tracking and implantable healthcare monitoring. In such cases, energy harvesting is a viable solution. Vibrational energy harvesting is abundantly available in the environment. These vibrations usually are low in frequency and amplitude. Conventional vibrational harvesters convert the environmental vibrations into electrical signals; however, they suffer from low‐voltage outputs and narrow bandwidths, limiting the harvesting to a small range of frequencies. Herein, a new mechanical harvester is introduced using a magnetic frequency up‐converter. It is implemented using attractive‐force magnetic coupling between a soft magnet and a permanent magnet to convert low‐frequency vibrations into high‐frequency pulses. Combined with a piezoelectric generator, the harvester generates a high output voltage for an extended bandwidth of operation. The proposed harvester shows a 50.15% increase in output voltage at the resonant frequency (12.2 Hz), resulting in 14.79 V at 1.0 g, with a maximum peak voltage of 16.28 V. The bandwidth of operation ranges from 10.77 to 22.16 Hz (11.39 Hz), which when compared with a single‐beam harvester shows an increase of 3250% in the bandwidth, where the average power is greater for 92.56% of this bandwidth.

Many sensor applications require small and non-invasive methods of powering, such as marine animal tracking and implantable healthcare monitoring. In such cases, energy harvesting can be a viable solution. Vibrational energy harvesting is abundantly available in the environment.These vibrations usually are low in frequency and amplitude. Conventional vibrational harvesters convert the environmental vibrations into electrical signals; however, they suffer from low voltage outputs and narrow bandwidths, limiting the harvesting to a small range of frequencies. In this work, a new mechanical harvester is introduced using a magnetic frequency up-converter. It is implemented using attractive-force magnetic coupling between a soft magnet and a permanent magnet to convert low-frequency vibrations into high-frequency pulses.Combined with a piezoelectric generator, the harvester generates a high output voltage for an extended bandwidth of operation. The proposed harvester shows a 50.15% increase in output voltage at the resonant frequency (12.2 Hz), resulting in 14.79 V at 1.0 g, with a maximum peak voltage of 16.28 V. The bandwidth of operation ranges from 10.77 Hz to 22.16 Hz (11.39 Hz), which compared to a single-beam harvester shows an increase of 3250% of the bandwidth, where the average power is greater for 92.56% of this bandwidth.

Porous microneedles (MNs) offer broad advantages such as fluid capture and filtration. Compared to hollow MNs, fluid injection through porous MNs causes a broader diffusion spread. Herein, three MN designs with a constant pore size and controlled pore locations are fabricated and compared, using two‐photon polymerization (2PP), by examining factors such as diffusion spread, mixing capabilities, and mechanical resilience. Results show that the porous MN can cover 16 times the injection area than that of the hollow MN. Porous MNs also show good mixing capabilities with two fluids. Mechanical compression results reveal that one porous MN can withstand a load of 0.6 N.

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