All-Silicone 3D Printing Technology: Toward Highly Elastic Dielectric Elastomers and Complex Structures

Silicone elastomers have been shown to be well-suited for dielectric elastomer actuators (DEA), mainly due to their unique combination of properties such as, high elasticity and reliability, fast electromechanical response, and high thermal stability. 3D printing of silicones can be achieved by empl...

Full description

Saved in:
Bibliographic Details
Published in:ACS applied polymer materials 2023-10, Vol.5 (10), p.7936-7946
Main Authors: Tugui, Codrin, Cazacu, Maria, Manoli, Daniel Marcel, Stefan, Alin, Duduta, Mihai
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Silicone elastomers have been shown to be well-suited for dielectric elastomer actuators (DEA), mainly due to their unique combination of properties such as, high elasticity and reliability, fast electromechanical response, and high thermal stability. 3D printing of silicones can be achieved by employing either costly and sensitive metal catalysts, low-viscosity precursors with complex chemical structures that are sometimes difficult to reproduce, or rheological modifiers or by incorporating reinforcing fillers (e.g., silica). Here, we present a formulation for 3D printing consisting only of α,ω-bis­(trimethyl­siloxy)­poly­(dimethyl­siloxane-co-methylthio­propylsiloxane) with a molecular weight M n = 55000 g/mol (much higher than what the literature reports) and 9.1 mol % vinyl groups as the base polymer and α,ω-bis­(trimethylsiloxy)­poly­(dimethyl­siloxane-co-methylthio­propyl­siloxane) with M n = 7000 g/mol and 5 mol % thiol groups as a cross-linking agent, along with 2,2-dimethoxy-2-phenyl­acetophenone (DMPA) as the photocatalyst, showing the optimal thiol/vinyl molar ratio of 0.047. The impact of UV exposure time on the proposed cross-linking system was investigated via FTIR spectroscopy and compression tests, revealing fast curing rates and gelation times of less than 1 s. As a demonstration, the printing platform produced a rubber grid consisting of 24 printing layers that can endure 100 compressive cycles at 50% strain without hysteresis. Moreover, the 3D-printed silicone ink generates elastomers with an elongation at break of 221%, a Young’s modulus of 0.29 MPa, and a stress decay
ISSN:2637-6105
2637-6105
DOI:10.1021/acsapm.3c01190