Pulse: Metal NFC Business Card

Overview

Pulse is a custom metal NFC business card that shares contact information instantly when tapped with a smartphone. The card is laser engraved from anodized aluminum and embeds an NFC sticker with a ferrite isolation layer to achieve reliable read performance through a metal substrate.

The Problem with NFC on Metal

NFC relies on inductive coupling between the reader and the card's antenna. Metal surfaces interfere with this by generating eddy currents that cancel the magnetic field before it reaches the antenna. Placing an NFC sticker directly on aluminum makes it unreadable.

The fix was adding a ferrite sheet between the sticker and the aluminum. Ferrite is magnetically permeable but electrically resistive, so it directs the field through the antenna while blocking eddy currents in the metal beneath. Getting the right ferrite thickness and sticker spec took three sticker revisions and two material trials before hitting 100% read reliability.

Design & Fabrication

The layout was designed in AutoCAD at standard credit card dimensions (85.6 × 54mm). The front featured a crescent moon motif and my name. The back had additional crescent moon designs and an area for the NFC. Material selection landed on 0.8mm anodized aluminum with a matte finish. The anodized coating reduces laser reflectivity for cleaner engraving results. Early prototypes had centering issues, which were solved by registering the top-left corner of the card as a fixed reference point in the laser software. The final version went through three full manufacturing cycles to get there.

Results

The cards read reliably on both Android and iOS without any additional app. Future plans include a thinner custom-cut ferrite layer to reduce overall card thickness.