Flexible and printed magnetic field sensors

Work with spintronic functional elements for flexible magnetic field sensors, we was interested
in improving their performance, relying on new materials and metrological approaches. We
employ novel fabrication technics as an alternating magnetic field activation of self-healing of
percolation network [1]. It allows to fabricate printable magnetoresistive sensors revealing an
enhancement in sensitivity of more than one and two orders of magnitude, relative to previous
reports. Printed electronics are attractive due to their low-cost and large-area processing
features, which have been successfully extended to magnetoresistive sensors and devices [2].
This technology was enabled initially, by thin films magnetic field sensors, embedded in a soft
and flexible format to constitute magntosensitive electronic skin (e-skins). But now we
demonstrate what interactive electronics, based on flexible spin valve switches [3] or printed
and stretchable Giant Magnetoresistive Sensors, could act also as a logic elements, namely
momentary and permanent (latching) switches. All this printing technology aspects are yet to
be developed to comply with requirements to mechanical conformability of on-skin appliances.
Due to the fact that the metallic layer is subjected to unsteady mechanical stresses, deposition
of the magnetic sensor onto few microns thick non-rigid substrate creates a numerous
problems, and the strain sensitivity is the first effect which have to be discussed. The
thermoelectric effect is the second effect that also have to be considered in order to minimize
thermal errors. These aspects will be discussed more detailed in this contribution.

References

[1] R. Xu, Nature Communications 13, 6587 (2022)
[2] E. S. Oliveros Mata, Applied Physics A 127, 280 (2021)
[3] P. Makushko, Adv. Funct. Mater. 31, 2101089 (2021)
[4] M. Ha, Adv. Mater. 33, 2005521 (2021)