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The huge plastic production and plastic pollution are considered important global issues due to environmental aspects. One practical and efficient way to address them is to replace fossil-based plastics with natural-based materials, such as cellulose. The applications of different cellulose products have recently received increasing attention because of their desirable properties, such as biodegradability and sustainability. In this regard, the current study initially reviews cellulose products’ properties in three categories, including biopolymers based on the cellulose-derived monomer, cellulose fibers and their derivatives, and nanocellulose. The available life cycle assessments (LCA) for cellulose were comprehensively reviewed and classified at all the stages, including extraction of cellulose in various forms, manufacturing, usage, and disposal. Finally, due to the development of low-carbon materials in recent years and the importance of greenhouse gases (GHG) emissions, the proposed solutions to make cellulose a low carbon material were made. The optimization of the cellulose production process, such as the recovery of excessive solvents and using by-products as inputs for other processes, seem to be the most important step toward making it a low carbon material.

Fabrication of dense ceramic articles with intricate fine features and geometrically complex morphology by using a relatively simple and the cost‐effective process still remains a challenge. Ceramics, either in its green‐ or sintered‐form, are known for being hard yet brittle which limits further shape reconfiguration. In this work, a combinatorial process of ceramic robocasting and photopolymerization is demonstrated to produce either flexible and/or stretchable ceramic green‐body (Flex‐Body or Stretch‐Body) that can undergo a postprinting reconfiguration process. Secondary shaping may proceed through: i) self‐assembly‐assisted shaping and ii) mold‐assisted shaping process, which allows a well‐controlled ceramic structure morphology. With a proposed well‐controlled thermal heating process, the ceramic Sintered‐Body can achieve >99.0% theoretical density with good mechanical rigidity. Complex and dense ceramic articles with fine features down to 65 μm can be fabricated. When combined with a multi‐nozzle deposition process, i) self‐shaping ceramic structures can be realized through anisotropic shrinkage induced by suspensions' composition variation and ii) technical and functional multiceramic structures can be fabricated. The simplicity of the proposed technique and its inexpensive processing cost make it an attractive approach for fabricating geometrically complex ceramic articles with unique macrostructures, which complements the existing state of‐the‐art ceramic additive manufacturing techniques.

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Soft conductive elastomers with low hysteresis over a wide range of stretchability are desirable in various applications. Such applications include soft sensors with a long measurement range, motion recognition, and electronic skin, just to name a few. Even though the measurement capability of the sensors based on soft materials has been greatly improved compared to the traditional ones in recent years, hysteresis in the loading and unloading states has limited the applications of these sensors, thereby negatively affecting their accuracy and reliability. In this work, conductive elastomers with near-zero hysteresis have been formulated and fabricated using 3D printing. These elastomers are made by combining highly stretchable dielectric elastomer formulations with a polar hydrophobic ionic liquid and polymerizing under ultraviolet light. High-performance piezoresistive sensors have been fabricated and characterized, with a 10-fold stretchability and low hysteresis (1.2%) over long-term stability (more than 10 000 cycles under cyclic stress) with a 20 ms response time. Additionally, the current elastomers displayed fast mechanical and electrical self-healing properties. Using 3D printing in conjunction with some of our structural innovations, we have fabricated smart gloves to show this material's wide range of applications in soft robots, motion detection, wearable devices, and medical care.

Dielectric elastomers are soft and perfect insulator polymers able to produce large strains with high energy density under the effect of applied high voltage. However, their use in practical applications is hindered by the need for high voltage to actuate. Also, they need prestretching between rigid frames to produce out-of-plane shape changes, which may reduce their lifetime. Here, we synthesized a set of elastomers with high permittivity (from 20 to reach 60 at 10 3 Hz), controllable thermal properties (T g vary from −15 to −50 °C), and good mechanical properties (Young's modulus values between 0.48 and 0.2 MPa at 20% strain). Due to the high permittivity, an actuator made of the material was able to respond to a low voltage of 700 V and produce a 6.5% area strain for more than 10 000 cycles. Moreover, the elastomers were found to produce giant free-end bending displacements with prespecified bending direction (bend to the side of the positive electrode) under a low electric field, which we called programmable dielectric elastomers (PDE). Besides the aforementioned characteristics and performance, the formulated elastomers are suitable for UV-based three-dimensional (3D) printing. The printability of the elastomers allows fabricating programmable complex geometries to produce high deformations under relatively low electric fields.

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Laser powder bed fusion (LPBF), like many other additive manufacturing techniques, offers flexibility in design expected to become a disruption to the manufacturing industry. The current cost of LPBF process does not favor a try-and-error way of research, which makes modelling and simulation a field of superior importance in that area of engineering. In this work, various methods used to overcome challenges in modeling at different levels of approximation of LPBF process are reviewed. Recent efforts made towards a reliable and computationally effective model to simulate LPBF process using finite element (FE) codes are presented. A combination of ray-tracing technique, the solution of the radiation transfer equation and absorption measurements has been used to establish an analytical equation, which gives a more accurate approximation of laser energy deposition in powder-substrate configuration. When this new analytical energy deposition model is used in in FE simulation, with other physics carefully set, it enables us to get reliable cooling curves and melt track morphology that agree well with experimental observations. The use of more computationally effective approximation, without explicit topological changes, allows to simulate wider geometries and longer scanning time leading to many applications in real engineering world. Different applications are herein presented including: prediction of printing quality through the simulated overlapping of consecutive melt tracks, simulation of LPBF of a mixture of materials and estimation of martensite inclusion in printed steel.