Semicrystalline Polythiophene-Based Nanoparticles Deposited from Water on Flexible PET/ITO Substrates as a Sustainable Approach toward Long-Lasting Solid-State Electrochromic Devices

info:eu-repo/grantAgreement/EC/H2020/734834/EU FCT/MEC (UIDB/50006/2020). PhD grant SFRH/BD/139171/2018 from FCT/MCTES. We are very grateful to Dr. Carlos Pinheiro and Ynvisible company for discussions and assistance in the assembly of the electrochromic devices.We report the use of films of poly(3-hexylthiophene-2,5-diyl) nanoparticles (P3HT-NPs) prepared with the reprecipitation method employing water as solvent in the absence of surfactants for solid-state electrochromic devices (ECDs) and prove that these displays present enhanced properties when compared to similar ECDs with thin films deposited from chloroform. Films of differently sized nanoparticles (100 to 400 nm) were prepared and spray-coated on flexible PET-ITO substrates and tested for electrochromic properties. ECDs with switching times (t(90)) of 4 s were obtained using P3HT-NPs with a diameter of 100 nm, while those built using P3HT thin film presented longer switching speeds over 13 s for reduction (bleached to colored state). Additionally, the devices were subjected to 1000 cycles using -1.5 V/1.5 V, and the displays using P3HT 100 nm NPs presented higher transmittances (Delta(T) = +/- 20%) when compared with devices with P3HT thin film due to a more efficient oxidation step. Our data show that the availability of colloidal nanoparticles made of conjugated polymers deposited from water is an environmentally sustainable strategy leading to electrochromic devices with improved properties.authorsversionpublishe

Learning through interactive artifacts:Personal fabrication using electrochromic displays to remember Atari women programmers

In recent years makerspaces have gained traction as an environment where makers and tinkerers can freely create artefacts with digital fabrication tools. They are particularly suited for introducing new fabrication techniques because these spaces support hands-on experiences. Electrochromic displays are one such technology that has become possible to fabricate using new techniques and off-the-shelf tools which lends itself to be used in a workshop setting. Leveraging this development, we facilitated a makerspace workshop that introduced participants to this new technology. To limit the scope of the workshop outcome we used the little known history of female developers of video games (Atari) from the 1970s and 1980s as a design framing. The participants (undergraduates, 16 female, 2 male, aged 19–21 years) explored the Atari women’s role in development and through this exploration they created artifacts using novel electrochromic displays as designed responses. Throughout the workshop participants answered daily questionnaires and kept records of their progress. Our analysis of the questionnaires and the resulting projects suggests that having a relatable and meaningful context increases both motivation and engagement of the participants. We discuss the extrinsic motivations that enhance engagement, and provide suggestions for introducing new technologies in the makerspace context