Entirely flexible on-site conditioned magnetic sensorics

Being soft and compliant, flexible electronics conform to synthetic or biological tissues. Processing of the data acquired using flexible devices is typically done using external rigid electronics, which limits the unobtrusiveness, narrows the system bandwidth and lowers the signal-to-noise ratio. Here, we demonstrate the first entirely flexible integrated magnetic field sensor system consisting of a flexible giant magnetoresistive bridge on-site conditioned using high-performance IGZO-based electronic circuitry. The flexible readout electronics yields a record high overall gain of 48.6 dB and a remarkably high signal-to-noise ratio of 56 dB. The system detects magnetic fields with a sensitivity of 25 V/V/kOe and outperforms the responsiveness of commercial fully integrated rigid magnetic sensors by at least one order of magnitude, whereas all components stay fully functional while bent to a radius of 5 mm. We outline potential application directions and realized two demonstrators, namely a magnetic switch and a proximity sensing device with a low power consumption of 250 µW even when used to trigger an external LED, employed as visual output. Our high-performance flexible magnetosensory system represents a key step towards entirely flexible electronics, capable of sensing and processing signals without the need of rigid elements.