A miniaturized Rogowski current transducer with wide bandwidth and fast response

Abstract

The miniaturization of the 3D Rogowski current transducer down to the micro-scale is essential for device integration and expansion of its application scope, particularly for 'lab-on-a-chip' systems. However, fabrication of 3D miniaturized Rogowski coils remains challenging as most relative methods still rely on the 2D micromachining process. In this paper, a miniaturized Rogowski coil current transducer was fabricated using an improved femtosecond laser wet etching technology and a metal microsolidification process, in which a metal alloy with a relatively high melting point was used and a robust but simple packaging structure based on a conical electrode was developed. The results show that the miniaturized Rogowski coil current transducer reveals a response time of less than 1 ns, high sensitivity and good detection capability for high-frequency electrical signals. The miniaturized Rogowski coil can easily be integrated into functional microsystems and will be widely applicable for high-frequency electric signal detection and circuit protection.

Etching-assisted femtosecond laser modification of hard materials

“…Another important application is using the fabricated microchannels or microstructures as the mold for replicating polymer or metal microstructures [92][93][94][95][96] . Chen et al demonstrated the fabrication of polymer planar convex microlens arrays and compound eyes by replication of silica concave microlens arrays, which were fabricated by wet-etching-assisted femtosecond laser modification 94,95 , as the diagram shown in Fig.…”

“…7(b) -7(d). Meanwhile, by injecting of metal or metal alloys into 3D silica microchannels, various complicated metal microstructures are fabricated with large aspect ratios, such as micro-coils with operating bandwidth can be reached to 10 GHz 93 .…”

Femtosecond Laser Microfabrication of Artificial Compound Eyes

“…In contrast, femtosecond laser micromachining introduces a "cold" processing approach that minimizes damage to the surrounding area and facilitates ultra-high precision micro-/nanofabrication [55][56][57]. Therefore, femtosecond laser micromachining technology not only fulfills the demands for flexible three-dimensional processing of devices, but also achieves downsizing [58][59][60][61][62][63][64][65], establishing itself as a potent tool for the fabrication of microlenses in compound eyes.…”

MEMS Rogowski coil current sensor with spiral return coil

“…Though it depends on specific system, one can think of currents reaching 100 A and higher within a short time of the microsecond order. Features of existing cur-rent sensors [1][2][3][4][5][6][7][8][9][10][11] are presented in Table 1. In this study, we selected Rogowski coil that features linearity of measurement up to heavy current, small temperature fluctuation, and compatibility with semiconductor processes.…”