Few examples of technical and biomedical applications of bistable magnetic microwires are shown. Particularly, application of microwires in civil engineering are shown for sensing the mechanical stress in concrete, steel structure or steel cable by simple gluing it on the surface of studied structure. On the other hand, biomedical applications for sensing the stress, temperature, and position inside the human or animal body are shown. Experiments with pig intestine cells points to the biocompatibility of glass coated microwires.

Compared to other sensors, such as radio‐frequency identification sensors, microwires have a significant advantage due to their small dimensions and contact‐free reading. The most important advantage is that a microwire is considered to be a biocompatible material due to the glass‐coating insulator. This is particularly applicable in various titanium implants (dental, knee joint, replacement of damaged skull part, repair of the femur, etc.). The temperature dependence of the switching field can be employed to monitor inflammatory processes. In this contribution we present the influence of molybdenum (Mo) content on the magnetic properties and thermal treatment in order to obtain a strong variation of the switching field to temperature. We show that stress annealing of a FeMo9BCu microwire at 775 K under an applied axial stress of 309 MPa leads to the strongest variation in a temperature range from 300 to 315 K, which is highly desirable for biomedical applications.

The control of biomechanical processes in the tissue-implant interface and thermal changes created by friction or inflammatory processes in the implant and its environment represent the key validating processes of the postimplanting process. It is crucial for a patient and their health to minimize the invasiveness of the temperature measuring processes and the inner mechanical stress in the implant-tissue interface. For the purpose of these measurements, amorphous magnetic glass-coated microwires are the most suitable. Compared with other sensors, such as radio frequency identification sensors, the microwires have a significant advantage due to their dimensions (∼2 cm × 50 µm) (because of which the sensor almost does not interfere with the inner implant structures), their production is relatively cheap, and only ∼20 mm microwire is needed for the functional sensor. This paper is concerned with the testing of more types of microwire fixation in an implant and the impact of the fixation; it deals with necessary magnetic properties of a microwire and their dependence on the temperature. Microwire made of master alloy Fe 78 W 5 B 17 was created and fixed in four ways: 1) on one end; 2) on two ends; 3) in the middle; and 4) along its full length. The results show that the optimal way of fixation is the one along the full length of a microwire; however, the final signal is influenced by both, the type and volume of the applied fixation material. The highest sensitivity of the designed microwire was in the range of 120-140°C with no fixation and only with the full length fixation, this sensitivity decreased to 40-50°C, which is a level close to the level required for biomedical applications (35-42°C).Index Terms-Amorphous magnetic glass-coated microwires, magnetoelasticity, smart implants, switching field.

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