A device for acquiring mechanical loads on mechanically loaded bodies is provided. The device exhibits a resonance-capable micro-bridge structure, an alternating voltage source with a variable frequency, an impedance measuring device for acquiring the impedance of the micro-bridge structure and an electronic unit for receiving determined impedance values and changing the frequency of the alternating voltage source. By exciting the micro-bridge structure and measuring its impedance, a conclusion can be drawn as to the expansion-dependent resonance frequency, which in return makes it possible to determine the expansion, and hence the mechanical load. Such a device is sufficiently accurate, and largely independent of outside influences.