Claus Schelde Jacobsen's field of expertise is novel materials with potentially useful electric and/or magnetic properties, which in the long run may prove applicable for new types of electronic and electrotechnical devices. Examples include:

• Optimisation of spin injection from ferromagnetic thin-films into conventional semiconductor structures; the spins carry magnetic moments, which may be manipulated by means of electric and magnetic fields. 
• Optimisation of the properties of ceramic superconductors (i.e. high temperature superconductors) by deposition on specially designed substrates, where the crystal structure of the superconductor becomes more perfect;  this is of great importance both for applications in electronics as well as for development of superconducting cables, which may be used to carry electricity and for creating high magnetic fields .

He also teaches courses in introductory physics, electromagnetism, instrumentation and measurements, statistical physics, physics of electronic quantum devices, etc.