I. Introduction
The reliability and stability of bearings are key factors restricting the operational performance of rotating machinery [1], [2], [3]. With the rapid development of gas turbines, aeroengines, and other equipment, the requirements for the dynamic performance, service life, and stability of rolling bearings are becoming more stringent [4], [5]. Rolling element slip, cage instability, cage cracking, and twisted fractures are the main causes of rolling bearing failure and reliability reduction [6], [7], [8]. Traditional sensing methods, such as vibration sensors, fiber-optic sensors, and high-speed photography methods, are limited by their structural integrity and reliance on external power sources [9], [10], [11]. The installation location of sensors is limited, and the lack of self-powering and wireless transmission capabilities significantly hinders the development of intelligent rolling bearings (IRBs). Therefore, it is essential to apply advanced technology to develop a high-precision and compact IRB to wirelessly monitor the health of bearings.