Moderate-Density Flexible Hybrid-Integrated Temperature-Magnetic Sensing Array Toward Motor-Drive Monitoring

Compact motor-drive and robotic actuation systems require conformal sensing hardware that can simultaneously acquire local temperature and magnetic-field information for thermal protection, condition monitoring, and feedback-oriented operation. Here, we report a flexible hybrid-integrated temperature-magnetic sensing array based on a 1.2 × 0.6 mm2 monolithic silicon die integrating a bandgap-referenced PTAT temperature channel and an amplified Hall magnetic channel. The die is assembled on an ultra-thin flexible printed circuit through conductive bonding, gold-wire interconnection, die thinning, and PDMS encapsulation to support compliant operation on curved electromechanical surfaces. Single-point tests show a temperature sensitivity of 5 mV/°C and a magnetic sensitivity of 96.6 mV/mT, corresponding to 483-fold amplification of the intrinsic Hall response; under bending radii ≥20 mm and temperatures from −40 to 125 °C, magnetic sensitivity drift remains within ±2% with channel interference below 1.2%; and a 6 × 6 array with 6 mm pitch demonstrates magnetic localization and spatial temperature mapping. These results support the device as a compact sensing-hardware prototype with potential for motor-drive monitoring and actuator-state perception; however, benchtop validation does not yet demonstrate closed-loop motor-control performance, and future motor-level tests are required.