Design and Implementation of a Miniaturized Spintronic-Based Proximity Sensor

This paper presents the design and implementation of a miniaturized, low-noise Magnetic Tunnel Junction (MTJ)-based proximity sensor with a high-performance readout channel. The MTJ-based proximity sensor consists of 1102 circular pillars of 100um diameter arranged in series, providing accurate detection of subtle interactions, such as a finger approaching the sensor. The system exhibits a 54 dB gain and a bandwidth of 1 kHz, with a noise power density of less than 30 nV/√Hz at 100 Hz, ensuring high precision. The proximity sensor demonstrated linear behavior for distances from 18 mm to 45 mm, with a sensitivity sufficient to detect low magnetic field variations. Experimental validation of the sensor shows a high degree of accuracy (R<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> = 0.9715), confirming its potential for use in touchless control, mobile technology, and industrial applications.