Transfer printing of GMR sensing elements for curved electronics

In the post-covid era, touchless interaction between human beings and environments is attracting more and more attentions. Sensors based on giant magnetoresistance (GMR) effect are widely considered as a workhorse to address this demand. However, the fabrication of GMR
multi-layer elements face many limitations (e.g., inappropriate to substrates with curved and/or rough surfaces) due to the layer thickness
dependence of performance. Here, we propose a transfer technique to overcome the aforementioned limitations. With the assistance of two
sacrificial layers, a large scale and wrinkle-free coverage is realized on
various substrates (of different materials, roughness, and curvatures) with little loss of GMR performance. Notably, such technique is easy
processing, without the need of any substrate deformation, temporary carriers or high-temperature processing. The transferred sensors are
integrated into skin-mountable electronics, successfully functioning as a human-machine interface.