DLP 4D‐Printing of Remotely, Modularly, and Selectively Controllable Shape Memory Polymer Nanocomposites Embedding Carbon Nanotubes

Abstract

An in-depth investigation on novel electro-activated shape memory polymer composites (SMPCs) for digital light processing 3D-Printing, consisting of a poly(ethylene glycol) diacrylate/poly(hydroxyethyl methacrylate) matrix embedding multi-walled carbon nanotubes (CNTs), is reported here. The composition of the photocurable (meth)acrylate system is finely tuned to tailor the thermomechanical properties of the matrix, whereas the effect of CNTs on the photoreactivity and rheological properties of the formulations is investigated to assess the printability. Electrical measurements confirmed that the incorporation of CNT into the polymeric matrix enables the electrical conductivity and thus the possibility to remotely heat the nanocomposite using the Joule effect. The feasibility to drive a shape memory cycle via Joule heating is proved, given that the high shape fixity (R f ) and shape recovery (R r ) ratios achieved (R f ≈ 100%, R r > 95%) confirmed the significant electrically-triggered responsiveness of such CNT/SMPCs. Finally, it is shown how to activate a modular and selective electro-activated shape recovery, which may ultimately envisage the 4D-Printing of remotely and selectively controllable smart devices.

Electroconductive Photo-Curable PEGDA-Gelatin/PEDOT:PSS Hydrogels for Prospective Cardiac Tissue Engineering Application

“…The presence of PEDOT:PSS caused a slightly reduction in the final Young's modulus of hydrogels with the same PEGDA:gelatin ratio, with no significant differences except for P2G1 and P2G1P0.3 samples. In agreement with previous reports (Sangermano et al, 2008;Gonzalez et al, 2017;Cortés et al, 2021), the presence of UV light absorbing fillers such as PEDOT:PSS may lead to UV shielding effect reducing photopolymerization kinetics of thick samples at increasing depth from the exposed surface. Therefore, the cross-linking degree of thick cylindrical hydrogels containing PEDOT:PSS was lower on the bottom portion of the samples, affecting the final mechanical properties.…”

Bio‐Based Piezo‐ and Thermoresistive Photocurable Sensing Materials from Acrylated Epoxidized Soybean Oil

“…[ 41 ] Furthermore, the increased G ′ values of the formulations containing rGO before the onset of photopolymerization indicate an increase in the viscosity of the formulations, which is clearly observed during the preparation of the samples. [ 39 ]…”

“…[35] In particular, different functional systems and devices have been prepared based on piezoresistive and thermoresistive materials obtained by the combination of carbon-based fillers and different thermoplastic polymers, [36,37] at the point that the use of carbonaceous materials in combination with photocurable systems have been extended to 3D printing [38] or even 4D printing. [39] However, despite these recent advances and up to our knowledge, there are not cases in which carbon-based fillers have been combined with UV curable bio-based resins in order to obtain piezoresistive and/or thermoresistive materials with improved sustainability, addressing therefore, both the functional and environmental needs of current society.…”

The Synergistic Role of Additive Manufacturing and Artificial Intelligence for the Design of New Advanced Intelligent Systems

“…Lately, such nanoparticles have been integrated into the printing process, leading to novel conductive inks, [ 37 ] with tunable conductive properties, which are used to manufacture electronic components [ 9 ] or selectively controllable smart devices via an electroactivated shape memory effect. [ 38 ] Through printing, the ink can cost effectively build microfluidic devices and a wide range of other electronic devices, including flexible electronics, with high resolution and strong metallic conductivity. [ 39 ]…”

“…inks, [37] with tunable conductive properties, which are used to manufacture electronic components [9] or selectively controllable smart devices via an electroactivated shape memory effect. [38] Through printing, the ink can cost effectively build microfluidic devices and a wide range of other electronic devices, including flexible electronics, with high resolution and strong metallic conductivity. [39] The emerging trend to print a wide palette of functional and smart inks, including electronic and biological inks, has made patient-specific wearable devices accessible to a wide range of people and enables smart biomedical implants for applications such as health monitoring and regenerative biomedicines.…”