A5010729913- Additive Manufacturing and 3D Printing Technologies
- Advanced Sensor and Energy Harvesting Materials
- Polymer composites and self-healing
- 3D Printing in Biomedical Research
- Dielectric materials and actuators
- Advanced Materials and Mechanics
- Ferroelectric and Piezoelectric Materials
- Pickering emulsions and particle stabilization
- Graphene research and applications
- Nuclear materials and radiation effects
- Electrospun Nanofibers in Biomedical Applications
- Micro and Nano Robotics
- Nanomaterials and Printing Technologies
- Supercapacitor Materials and Fabrication
- Energetic Materials and Combustion
- Fluid Dynamics and Heat Transfer
- Innovative Microfluidic and Catalytic Techniques Innovation
- Photopolymerization techniques and applications
- Analytical Chemistry and Sensors
- Cellular and Composite Structures
- Advanced Photocatalysis Techniques
- Polymer Foaming and Composites
- Microwave Dielectric Ceramics Synthesis
- Silicone and Siloxane Chemistry
Lawrence Livermore National Laboratory
2015-2024
Abstract Graphene is a two-dimensional material that offers unique combination of low density, exceptional mechanical properties, large surface area and excellent electrical conductivity. Recent progress has produced bulk 3D assemblies graphene, such as graphene aerogels, but they possess purely stochastic porous networks, which limit their performance compared with the potential an engineered architecture. Here we report fabrication periodic aerogel microlattices, possessing architecture...
Typically, mechanical metamaterial properties are programmed and set when the architecture is designed constructed, do not change in response to shifting environmental conditions or application requirements. We present a new class of architected materials called field responsive metamaterials (FRMMs) that exhibit dynamic control on-the-fly tunability enabled by careful design selection both material composition architecture. To demonstrate FRMM concept, we print complex structures composed...
Abstract 3D printing of multimaterial parts relies upon efficient mixing the ink components and a rapid response to composition changes. However, at low Reynolds numbers large Peclet numbers, disparate viscosity density inks poses challenge. In this study, performance active micromixers for non‐Newtonian is evaluated using both experiments computational fluid dynamics simulations. The efficiencies are compared with scaling relationships micromixers. Using detailed simulation results,...
The mixing of materials during additive manufacturing is a major benefit which allows one to compositionally and spatially tailor material properties, for example locally control the reactivity in fuel – oxidizer systems known as thermites. This work characterizes an active printhead used conjunction with 3D printing process Direct Ink Writing. Besides compositional control, this approach that it offers safe method working these materials, can otherwise be hazardous once mixed. Custom inks...
Abstract Additive manufacturing (AM) has recently shown great promise as a means to tailor wide range of material properties, both quasi‐static and dynamic. An example controlling the dynamic behavior is chemical energy release rate in composite energetic materials such thermites – which are subset pyrotechnics that use metal fuel oxide an oxidizer. Since these most hazardous once finely mixed, approach taken here formulate oxidizer separately they can be mixed on‐the‐fly. Herein,...
Abstract 3D printing of structures with compositional gradients requires accurate dispensing control to achieve desired profiles. Here, empirical data are used a model based on the microfluidic circuit analogy (MCA) project dispense rate profiles that yield improved accuracy in printed part. Since minor variation experimental setup for each session can result significant changes, calibration procedure is developed measure system response. This enables extraction MCA parameters specific print...
Abstract In this paper, inks for transparent elastomers that are formulated by matching the refractive index of silica and polysiloxanes described. The transmit up to ≈90% 700 nm light through 1 cm remain when solidified. solidified materials exhibit a thermochromic effect. This effect can be controlled mismatch. Transparency may increase or decrease as temperature increases, depending on mismatch base polysiloxane silica. It is found rheological properties ink depend distribution particles,...
Additive Manufacturing (AM), or 3D printing, is a powerful technology that revolutionizing the way designers create products across many industries. AM severely limited by lack of effective methods for in situ characterization multi-material properties and composition during printing. The ability to detect printed inks real time an emerging need wide range manufacturing applications. In this study, dielectric embedded metal microparticles matrix are measured characterized as function...
Addition of chemical blowing agents to polysiloxane resins produces foams with closed‐cell morphology. Combining this chemistry the 3D‐printing technique direct ink writing (DIW) permits creation architected controllable, hierarchical tiers porosity. Using a two‐component foaming ink, extent can be controlled by incorporating an active mixing printhead as part fabrication process. Changes in speed allows for situ control reaction where is directly correlated resulting that occurs upon...
Abstract Silicone elastomers have a broad variety of applications, such as soft robotics, biomedical devices, and structural metamaterials. The extrusion‐based method known direct ink write (DIW) has enabled the production additively manufactured silicone structures. However, this is limited to manufacturing mostly planar or pseudo‐3D Due low self‐supporting capabilities extruded strands for traditional silicone‐based “inks,” obtaining tall overhanging structures, structures comprised by...
3D printing of multi-material objects enables the design complex architectures such as printed electronics and devices. The ability to detect composition inks in real time is an enabling feature a wide range manufacturing sectors. In this study, dielectric properties microscale embedded metal particles matrix have been characterized using impedance measurements function particle size, shape, volume percentage frequency. Measurements were found agree well with calculations based on...
Refractive Index Matching Polysiloxanes can be printed by direct ink writing when they are mixed with the appropriate additives. However, these additives affect optical transparency, which is a useful property of polysiloxanes. In article number 2100974, Michael J. Ford, Jeremy M. Lenhardt, and co-workers describe how refractive index matching enable printability transparent siloxanes. These materials could for optics, scintillators, microfluidics.