Hot embossing

In hot embossing, a stamp pattern is replicated in a polymer film by applying pressure and heat. This allows for pattern transfer in materials that are not traditionally used for microfabrication such as biopolymers. During the past years, we have developed methods for hot embossing of high aspect ratio structures (AR > 10) in biodegradable polymers such as Poly(lactic acid) (PLLA) and poly(caprolactone) (PCL). For this purpose, we optimized the fabrication of Ni stamps at DTU Danchip.

Hot embossing for definition of microstructures in biodegradable polymer PLLA

Hot punching

In hot embossing, a residual layer connects patterned microstructures with the surrounding polymer film. Recently, we introduced hot punching as a promising method allowing fabrication of individual microcomponents due to penetration of the residual layer.  

Illustration of hot punching for the fabrication of biopolymer microcontainers for oral drug delivery. Bottom left: Poly(L-lactic acid) film with punched holes (diameter 300um); center and left: Punched PLLA microcontainers


  1. R.S. Petersen, R. Mahshid, N.K. Andersen, S.S. Keller, H.N. Hansen, A. Boisen ”Hot embossing and mechanical punching of biodegradable microcontainers for oral drug delivery”, Microelec. Eng. 133 (2015) 104-109

  2. R.S. Petersen, S.S. Keller, O. Hansen, A. Boisen, ”Fabrication of Ni stamp with high aspect ratio, two-leveled, cylindrical microstructures using dry etching and electroplating”, J. Micromech. Microeng. 25 (2015) 055021

  3. R.S. Petersen, S.S. Keller, A. Boisen, ”Hot punching of high-aspect-ratio 3D polymeric microstructures for drug delivery”, Lab Chip 5 (2015) 2576-2579

  4. J. Nagstrup, S.S. Keller, K. Almdal, A. Boisen “3D microstructuring of biodegradable polymers”, Microelec. Eng. 88 (2011) 2342-2344


Prof. Anja Boisen, Nanoprobes group, DTU Nanotech

Prof. Matthias Worgull, Karlsruhe Institute of Technology (KIT), Germany



Last updated 14.12.2016, Stephan Sylvest Keller