Apparatus and method for determining mechanical properties of a system

An apparatus for determining rheological, viscoelastic properties, of a biological system or a viscoelastic system, said apparatus comprising:

• a first contact element, which is an oscillatable contact element, and a second contact element arranged in such a manner relative to one another that they are operatively connected to one another by way of the biological system or viscoelastic system when determining the rheological, viscoelastic properties of the biological system or viscoelastic system;
• an excitation device for photothermally exciting the oscillatable contact element;
• and
• a detection device for detecting vibrations and hence the rheological, viscoelastic properties of the biological system or viscoelastic system in the excited oscillatable contact element, wherein both the excitation device and the detection device interact with the oscillatable contact element, wherein the apparatus is configured to excite the oscillatable contact element and hence the biological system or viscoelastic system to oscillate with different frequencies and/or with one or more frequency sweeps for determining the rheological, viscoelastic properties of the biological system or viscoelastic system in a frequency-resolved or frequency-dependent manner.