Actuatable optical device, method of fabricating the device, and use of a magnetic substance

A method of fabricating an actuatable optical device, the method comprising:

• forming, via a 3D printer, a three-dimensional structure including at least one optical element having at least one microfluidic cavity for accommodating a magnetic substance;
• and
• filling the at least one microfluidic cavity with the magnetic substance,
• wherein the three-dimensional structure is printed on one end of a fiber or a fiber bundle, wherein the three-dimensional structure further has a microcoil for generating a magnetic field with which an actuation of the at least one optical element can be monitored or controlled, and wherein the microcoil is arranged in such a way that it encloses the fiber or the fiber bundle at least in some part(s).