Magnetic binary encoding system based on 3D printing and GMI detection prototype

Abstract

In this work, the feasibility of a magnetic binary encoding system using 3D printing technology is analyzed. The study has a double interest, that is, the possibility of printing a 3D piece that contains the codified information and the development of a system for its decoding. For this purpose, magnetic nanoparticles (magnetite Fe 3 O 4 ) were embedded in a polymeric matrix of Polylactic Acid (PLA) and Poly-ε-caprolactone (PCL). Similar to a conventional barcode, a rectangular piece with an alternating pattern of strips with absence (only polymer) and a 5 wt% of embedded magnetic nanoparticles was 3D printed employing the Fused Deposition Modelling technique (FDM). The information was decoded by means of a Giant Magnetoimpedance (GMI) sensor-based prototype, by scanning the surface of the piece and measuring the changes in the magnetic field. As sensor nucleus, an amorphous soft magnetic wire of nominal composition (Co 0.94 Fe 0.06 ) 72.5 Si 12.5 B 15 was employed. The decoding prototype incorporates a homemade electronic sensor interface that permits, at the time, the GMI sensor excitation and the subsequent signal conditioning to optimize its response. The output signal enables the detection of the magnetite nanoparticles and the magnetic decoding of the encoded information (“1” and “0”, presence or absence of the magnetic nanoparticles, respectively). • Fabrication of 3D printable filaments with embedded magnetic nanoparticles (Fe 3 O 4 ). • 3D printing of a functional piece with encoded information (barcode). • Decoding of hidden (no visible) codes using low-cost GMI-based decoder.