The challenges of developing a micro electromagnetic power generator are to increase the flux density from the thin permanent magnet and reduce the resistance of the micro high-winding-density coil. To overcome these challenges, we propose a novel MEMS power generator for low-frequency-vibration energy harvesting employing a 16-poles thin magnet plate and a high-aspect-ratio spiral micro array coil. Transient magnetic analysis has proved that the multi-pole magnet thin plate (8.9 × 8.9 × t0.5 mm) magnetized by laser assisted heating helps increase the output power from the generator compared with the unidirectional one. The high-aspect-ratio spiral micro array coil (width: 80 µm, thickness: 160 µm, total turns: 144) fabricated by the combination of multilayer SU-8 micro moldings, copper plating, and silver paste screen printing is beneficial for increasing coil density and reducing resistance, thus improving output power. The vibration experiment showed that in terms of no consideration of spring and guideway structure, when the magnet is directly vibrated by an actuator, the induced voltage, generated power, and power density were 1.63 mV, 0.12 µW and 1.03 µW/cm³, respectively at an excitation frequency of 10 Hz with an amplitude of 2 mm. When a 3D-printed cantilever beam was adopted as the spring and guideway structure for the resonant prototype, the counterparts were 8.48 mV, 3.34 µW and 5.22 µW/cm³, respectively at 38 Hz and 2 mm excitation (corresponding to a vibration acceleration peak of 11.6 g).

开发微型电磁发电机的挑战是增加来自薄型永磁体的磁通密度并减小微型高绕组密度线圈的电阻。为了克服这些挑战，我们提出了一种新颖的MEMS发电机，该发电机采用16极薄磁体板和高纵横比螺旋微阵列线圈进行低频振动能量收集。瞬态磁分析已证明，与单向磁体相比，通过激光辅助加热磁化的多极磁体薄板（8.9×8.9×t0.5 mm）有助于增加发电机的输出功率。高纵横比螺旋微阵列线圈（宽度：80 µm，厚度：160 µm，总匝数：144）是由多层SU-8微成型件，镀铜，银浆丝网印刷有利于提高线圈密度和降低电阻，从而提高输出功率。振动实验表明，在不考虑弹簧和导轨结构的情况下，当磁体直接通过执行器振动时，感应电压，产生的功率和功率密度分别为1.63 mV，0.12 µW和1.03 µW / cm。^在图3中，分别以10Hz的激励频率和2mm的幅度。当采用3D打印的悬臂梁作为谐振原型的弹簧和导轨结构时，在38 Hz和2 mm激励下，对应的分别为8.48 mV，3.34 µW和5.22 µW / cm ³（对应于振动加速度峰值） 11.6克）。