TY  - GEN
TI  - Increasing the Efficiency of Thermoresponsive Actuation at the Microscale by Direct Laser Writing of pNIPAM
Y1  - 2022///
PB  - Universität
AV  - public
UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/32572/
CY  - Heidelberg
A1  - Spratte, Tobias
A1  - Geiger, Sophie
A1  - Colombo, Federico
A1  - Mishra, Ankit
A1  - Taale, Mohammadreza
A1  - Hsu, Li-Yun
A1  - Blasco, Eva
A1  - Selhuber-Unkel, Christine
KW  - soft microactuators
KW  -  direct laser writing
KW  -  two-photon-polymerization
KW  -  responsive 23 materials
KW  -  thermoresponsive hydrogels
N1  - This is the pre-peer reviewed version of the following article: Spratte, T., Geiger, S., 1 Colombo, F., Mishra, A., Taale, M., Hsu, L.-Y., Blasco, E., Selhuber-Unkel, C., Increasing the Efficiency of Thermoresponsive Actuation at the Microscale by Direct Laser Writing of pNIPAM. Adv. Mater. Technol. 2022, 2200714., which has been published in final form at https://doi.org/10.1002/admt.202200714.
ID  - heidok32572
N2  - Thermoresponsive hydrogels such as poly(N-isopropylacrylamide) (pNIPAM) are highly interesting materials for generating soft actuator systems. Whereas the material has so far mostly been used in macroscopic systems, we here demonstrate that pNIPAM is an excellent material for generating actuator systems at the micrometer scale. Two-Photon Direct Laser Writing was used to precisely structure thermoresponsive pNIPAM hydrogels at the micrometer scale based on a photosensitive resist. We systematically show that the surface- to-volume ratio of the microactuators is decisive to their actuation efficiency. The phase transition of the pNIPAM was also demonstrated by nanoindentation experiments. We observed that the mechanical properties of the material can easily be adjusted by the writing process. Finally, we found that not only the total size and surface structure of the microactuator plays an important role, but also the crosslinking of the polymer itself. Our results demonstrate for the first time a systematic study of pNIPAM-based microactuators, which can easily be extended to systems of microactuators that act cooperatively, e.g., in microvalves.
ER  -