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Design and Fabrication Challenges for Millimeter-Scale Three-Dimensional Phononic Crystals. CRYSTALS 2017. [DOI: 10.3390/cryst7110348] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Castles F, Isakov D, Lui A, Lei Q, Dancer CEJ, Wang Y, Janurudin JM, Speller SC, Grovenor CRM, Grant PS. Microwave dielectric characterisation of 3D-printed BaTiO3/ABS polymer composites. Sci Rep 2016; 6:22714. [PMID: 26940381 PMCID: PMC4778131 DOI: 10.1038/srep22714] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 02/22/2016] [Indexed: 11/17/2022] Open
Abstract
3D printing is used extensively in product prototyping and continues to emerge as a viable option for the direct manufacture of final parts. It is known that dielectric materials with relatively high real permittivity—which are required in important technology sectors such as electronics and communications—may be 3D printed using a variety of techniques. Among these, the fused deposition of polymer composites is particularly straightforward but the range of dielectric permittivities available through commercial feedstock materials is limited. Here we report on the fabrication of a series of composites composed of various loadings of BaTiO3 microparticles in the polymer acrylonitrile butadiene styrene (ABS), which may be used with a commercial desktop 3D printer to produce printed parts containing user-defined regions with high permittivity. The microwave dielectric properties of printed parts with BaTiO3 loadings up to 70 wt% were characterised using a 15 GHz split post dielectric resonator and had real relative permittivities in the range 2.6–8.7 and loss tangents in the range 0.005–0.027. Permittivities were reproducible over the entire process, and matched those of bulk unprinted materials, to within ~1%, suggesting that the technique may be employed as a viable manufacturing process for dielectric composites.
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Affiliation(s)
- F Castles
- Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom
| | - D Isakov
- Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom
| | - A Lui
- Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom
| | - Q Lei
- Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom
| | - C E J Dancer
- Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom.,International Institute for Nanocomposites Manufacturing (IINM), Warwick Manufacturing Group, University of Warwick, Coventry, CV4 7AL, United Kingdom
| | - Y Wang
- Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom
| | - J M Janurudin
- Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom
| | - S C Speller
- Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom
| | - C R M Grovenor
- Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom
| | - P S Grant
- Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom
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Lakhtakia A. From bioinspired multifunctionality to mimumes. BIOINSPIRED BIOMIMETIC AND NANOBIOMATERIALS 2015. [DOI: 10.1680/jbibn.14.00034] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The methodologies of bioinspiration, biomimetics and bioreplication are inevitably pointing to the incorporation of multifunctionality in engineered materials when designing ever more complex systems. Optimal multifunctionality is one of the defining characteristics of metamaterials. As fibrous materials are commonly manufactured from a variety of source materials, mimumes – that is, microfibrous multifunctional metamaterials – are industrially viable even today, as exemplified by mimumes of parylene C. The microfibrous morphology of mimumes enhances surface-dominated effects in comparison to those evinced by bulk materials.
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Affiliation(s)
- Akhlesh Lakhtakia
- NanoMM–Nanoengineered Metamaterials Group, Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, State College, PA, USA
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Diamond-Structured Photonic Crystals with Graded Air Spheres Radii. MATERIALS 2012; 5:851-856. [PMID: 28817011 PMCID: PMC5458971 DOI: 10.3390/ma5050851] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 04/24/2012] [Accepted: 05/02/2012] [Indexed: 11/17/2022]
Abstract
A diamond-structured photonic crystal (PC) with graded air spheres radii was fabricated successfully by stereolithography (SL) and gel-casting process. The graded radii in photonic crystal were formed by uniting different radii in photonic crystals with a uniform radius together along the Г‑Х direction. The stop band was observed between 26.1 GHz and 34.3 GHz by reflection and transmission measurements in the direction. The result agreed well with the simulation attained by the Finite Integration Technique (FIT). The stop band width was 8.2 GHz and the resulting gap/midgap ratio was 27.2%, which became respectively 141.4% and 161.9% of the perfect PC. The results indicate that the stop band width of the diamond-structured PC can be expanded by graded air spheres radii along the Г‑Х direction, which is beneficial to develop a multi bandpass filter.
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