Flexible Magnetoreceptor with Tunable Intrinsic Logic for On‐Skin Touchless Human‐Machine Interfaces

TLDR

Artificial magnetoception offers a novel, yet unexplored, means for human interaction, enabled by thin‑film magnetic field sensors in flexible electronic skins, but current e‑skins are limited to in‑plane field sensing, restricting them to basic proximity and angle detection and preventing use as switches or logic elements. The study demonstrates a novel magnetoreceptive platform for on‑skin touchless interactive electronics using flexible spin‑valve switches sensitive to out‑of‑plane magnetic fields. The system employs all‑metal Co/Pd spin valves with a synthetic antiferromagnet and perpendicular magnetic anisotropy, creating flexible magnetoreceptors that function as momentary and latching switches and are integrated into on‑skin interactive electronics. The flexible switches retain performance when bent to radii below 3.5 mm, endure hundreds of bending cycles, and enable intuitive, energy‑efficient, magnetically‑insensitive touchless human‑machine interfaces, offering new functionalities for electronic skins.

Abstract

Abstract Artificial magnetoception is a new and yet to be explored path for humans to interact with the surroundings. This technology is enabled by thin film magnetic field sensors embedded in a soft and flexible format to constitute magnetosensitive electronic skins (e‐skins). Being limited by the sensitivity to in‐plane magnetic fields, magnetosensitive e‐skins are restricted to basic proximity and angle sensing and are not used as switches or logic elements of interactive wearable electronics. Here, a novel magnetoreceptive platform for on‐skin touchless interactive electronics based on flexible spin valve switches with sensitivity to out‐of‐plane magnetic fields is demonstrated. The technology relies on all‐metal Co/Pd‐based spin valves with a synthetic antiferromagnet possessing perpendicular magnetic anisotropy. The flexible magnetoreceptors act as logic elements, namely momentary and permanent (latching) switches. The switches maintain their performance even upon bending to a radius of less than 3.5 mm and withstand repetitive bending for hundreds of cycles. Here, flexible switches are integrated in on‐skin interactive electronics and their performance as touchless human‐machine interfaces is demonstrated, which are intuitive to use, energy efficient, and insensitive to external magnetic disturbances. This technology offers qualitatively new functionalities for electronic skins and paves the way towards full‐fledged on‐skin touchless interactive electronics.