# Influence of DMSO Non-Toxic Solvent on the Mechanical and Chemical Properties of a PVDF Thin Film
## 4 Conclusions and Future Works  
There are several experimental protocols to produce PVDF-based thin films described in the literature. However, the majority of them use toxic solvents such as DMF or methyl-ethyl-ketone (MEK), which are potentially harmful for users. Therefore, in order to produce an actuator free of toxic solvents (crucial for biomedical applications), in the present study, DMSO was chosen to create a PVDF-based film. Even though several authors have pointed to the possibility of using this solvent, only a few studies can be found in the literature. Hence, it is important to explore the properties of PVDF-based actuators produced by different protocols: especially those using non-toxic solvents. Having non-toxicity and strong piezoelectric behaviour as principal objectives in this study, our research team found an optimal ratio of \(12/88\%\)\(w/w\) PVDF/DMSO to obtain a more fluid mixture that facilitates the dissolution of the PVDF powder. Moreover, the best temperature for PVDF dissolution was also successfully achieved. A very low temperature would increase the dissolution time, while a high temperature could degrade the material. Therefore, a temperature of \(50\)\({}^{\circ}\)C was the ideal value to develop a suitable experimental protocol.  
Characterization of the material revealed that the inclusion of IL changes all the properties analysed, such as the Young's modulus (\(E\)), the yield stress (\(\sigma_{Yield}\)) and the \(\beta\) phase content. Nevertheless, considering similar ratio conditions, the use of a different solvent does not evidence deep changes to the material's properties, which points to the possible use of DMSO as a replacement solvent for hazardous alternatives. In the future, we aim to study the electro-mechanical properties and the response of the PVDF-based smart material to investigate even further its use in biomedical applications. Given the promising results obtained for the properties of this polymeric material, our research team intends to develop a biomedical device using a piezoelectric PVDF thin film as the main element.  
With this study, our research team hopes to have contributed significantly to the knowledge about piezoelectric PVDF-based materials and the potential use of these smart soft materials in future biomedical applications.  
The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/app14083356/s1](https://www.mdpi.com/article/10.3390/app14083356/s1)]([https://www.mdpi.com/article/10.3390/app14083356/s1](https://www.mdpi.com/article/10.3390/app14083356/s1)), Supplementary video: Tensile test (sped up 15 times).  
Conceptualization, A.D.A. and P.M.; investigation, A.D.A.; methodology, A.D.A.; formal analysis, A.D.A. and A.M.T.; writing--original draft, A.D.A.; writing--review and editing, A.D.A., A.M.T. and P.M.; supervision, P.M. All authors have read and agreed to the published version of the manuscript.  
[PERSON] (A.D.A) gratefully acknowledges funding from Fundacao para a Ciencia e a Tecnologia (FCT), Portugal, under grant SFRH/BD/147807/2019. [PERSON] (A.M.T.) acknowledges grant 2020.08718.BD; [PERSON] (P.M.) gratefully acknowledges funding from FCT through INEGI under LAETA, project UIDB/50022/2020.  
The raw data supporting the conclusions of this article will be made available by the authors on request.  
The authors state that they have no financial, professional or other personal involvement in any product, service and/or company that would possibly affect their stance.