Micromechanical sensors

In the past, we have developed processes for the fabrication of SU-8 microcantilevers with several steps of UV photolithography. Additionally, biodegradable polymer microcantilevers have been produced using nanoimprint lithography (NIL). This knowledge is the basis for development of novel micromechanical sensors in collaboration with other research groups. The Biomaterial Microsystems group is actively involved in the "The Danish National Research Foundation and Villum Foundation’s Center for Intelligent Drug delivery and sensing Using microcontainers and Nanomechanics - IDUN". In IDUN Sensor the research focuses on the development of new sensor platforms for pharmaceutical applications.

Carbon based micromechanical sensors

The BIOMIC group contributes to IDUN Sensor with fabrication of carbon based micromechanical sensors (Carbon MEMS). Micromechanical string resonators (micro guitar strings) have been obtained through pyrolysis of photoresist patterned by UV photolithography. In future, the pyrolytic carbon string resonators will be applied for characterization of drugs and polymers.

Micromechanical sensors for (bio)polymer characterization

We have spray coated thin films of various polymers on nanomechanical string resonators based on SiN. The measurement of the resonant behaviour during controlled temperature changes allowed for the extraction of thermal properties such as glass transition temperature or beta-relaxation of the materials. Si and SU-8 microcantilevers have been coated with biodegradable polymer films through spray coating. The gradual degradation of the polymers has been characterized by monitoring of the changes of the resonance frequency after immersion in media with enzymes such as Proteinase K. This allows for example the characterization of biopolymer degradation in biorelevant conditions such as gastric or intestinal media.


  1. M. Kurek, F.K. Larsen, P.E. Larsen, S. Schmid, A. Boisen, S.S. Keller, Nanomechanical pyrolytic carbon resonators: Novel fabrication method and characterization of mechanical properties”, Sensors 16 (2016) 1097

  2. S. Bose, S.S. Keller, A. Boisen, K. Almdal, ”Microcantilever sensors for fast analysis of enzymatic degradation of poly(D,L-lactide)”, Polym. Deg. Stab. 119 (2015) 1-8

  3. S. Bose, S. Schmid, T. Larsen, S.S. Keller, A. Boisen, K. Almdal, “Micromechanical fast quasi-static detection of a and b relaxations with nanograms of polymer”, J. Polymer Sci. B, 53 (2015) 1035-1039

  4. S. Bose, S. Schmid, T. Larsen, S.S. Keller, P. Sommer-Larsen, A. Boisen, K. Almdal ”Micromechanical string resonators: Analytical tool for thermal characterization of polymers”, ACS Macro Lett. 3 (2014) 55–58

  5. P. Colombi, P. Bergese, E. Bontempi, L. Borgese, S. Federici, S.S. Keller, A. Boisen, L.E. Depero “Sensitive determination of the Young’s modulus of thin films by polymeric microcantilevers”, Meas. Sci. Technol. 24 (2013) 125603

  6. S.S. Keller, N. Feidenhans’l, N. Fisker-Bødker, D. Soulat, A. Greve, D. Plackett, A. Boisen “Fabrication of biopolymer cantilevers using Nanoimprint lithography”, Microelec. Eng. 88 (2011) 2294-2296

  7. S.S. Keller, L. Gammelgaard, M.P. Jensen, S. Schmid, Z.J. Davis, A. Boisen “Micromechanical sensors for the measurement of biopolymer degradation” Proceedings IEEE MEMS (2011) 457-460

  8. S. Keller, D. Haefliger, A. Boisen, Fabrication of thin SU-8 cantilevers: initial bending, release and time-stability, J. Micromech. Microeng. 20 (2010) 045024-045035



Prof. Anja Boisen, Nanoprobes Group, DTU Nanotech

Prof. Silvan Schmid, Micro and Nano Sensors Group, TU Vienna

Prof. Kristoffer Almdal, PolSens Group, DTU Nanotech

 Last updated 19.12.2016, Stephan Sylvest Keller