Electromagnetic bi-directional micropumps (EMBM) are indispensable for the development of portable devices which enable fluid transportation in forward and reverse directions. However, the high disposal cost of rare-earth magnets attached to the fluidic part and the low pump density due to multiple motors limit their practical application in disposable multi-channel microfluidic applications such as droplet-based oscillatory-flow (DBOF) rapid PCR amplification. Therefore, this paper presented a low-cost, disposable, high-pump-density EMBM. To reduce the disposal cost, we separated the magnets from the disposable fluidic part and used cylindrical holes to store and guide the magnet, which resulted in the ability to reuse all the magnets. To increase the pump density, we used the combination of one motor and one multi-pole ring magnet to drive several channels simultaneously. A proof-of-concept prototype with a pump density of 0.28 cm⁻² was fabricated and experimentally evaluated. The fabricated micropump exhibited a maximum flow rate of 0.86 mL/min and a maximum backpressure of 0.5 kPa at a resonant frequency around 50 Hz. The developed multi-channel micropump with reusable magnets is highly beneficial to the development of low-cost and high-throughput rapid PCR amplification microchips and therefore can have a significant impact on timely infectious disease recognition and intervention.

We designed an electromagnetic microactuator with tunable dynamic characteristics using a thick-film FePt permanent magnet. FePt is a promising microactuator material because of its low Young’s modulus, high tensile strength, high ultimate strain as a structural material, and high remanence as a permanent magnet. By employing the laser-assisted heating magnetization method, we successfully reprogrammed the magnetization pattern of the FePt thick film, which led to the tuning of the dynamic characteristics of the 3.85 mm (l) × 0.82 mm (w) × 0.023 mm (t) FePt-based cantilever under the same alternating external magnetic field. When only the tip of the cantilever beam is magnetized, or when the tip and center of the same beam are magnetized in opposite phases, the peak gain of the frequency response characteristics of the former can be tuned to be 19 dB higher than that of the latter in the first-order mode and 19 dB lower than that of the latter in the second-order mode.

Aterahertz band (e.g., 150 GHz/300 GHz), with its broad bandwidth and potential for improved angular and distance resolution, is attracting attention for Beyond 5G/6G communication and sensing applications (radar, imager, etc.). However, as frequencies increase and wavelengths shorten, mechanical tolerances during integration can significantly impact performance (reflection, transmission, etc.), necessitating effective compensation mechanisms. In this paper, we verify the performance variations caused by mechanical tolerances in transmission-line-to-waveguide transitions, which integrate chips, substrates, and waveguides to transmit signals generated by the chip or receive signals from external sources. To overcome these challenges, a tunable-membrane microactuator is proposed, which adjusts the position of the back-short in the transition by using a flexible conductive membrane and a microactuator (dimension: ϕ10mm×16 mm, maximum stroke of the membrane: 707.7 μm, accuracy<1 μm). The proposed waveguide transition comprises a transmission line and a probe integrated on the multi-layer substrate, along with waveguide flanges and the tunable membrane microactuator. Based on simulation and measurement results, this paper demonstrates the capability of the proposed technology to tune the reflection/transmission losses and frequency bandwidth characteristics of a 249-GHz waveguide transition.