No abstract

No abstract

No abstract

Highly flexible biocompatible materials that are both thermally conductive and electrically insulating are important for implantable and wearable bioelectronics applications. The ability to thermally process these materials into useful structures using additive manufacturing approaches opens up new opportunities for its use in bespoke structures. Here we investigate the three-dimensional (3D) printing of a medical-grade thermoplastic polyurethane (PU) elastomer, which is thermally insulating and enhance its thermal and mechanical properties through the incorporation of boron nitride (BN) as a filler. Via a simple solution compounding approach, a highly flexible and thermally conductive BN nanoparticle/ PU composite has been developed and subsequently processed into simple bio-scaffolds structures via a 3D pneumatic melt extrusion printing process. The addition of up to 20% w/w of BN to the PU significantly enhances the tensile modulus by 659%, from 1.74 to 13.2 MPa, while supporting high mechanical flexibility. The thermal conductivity of 20% w/w BN/PU composite increases by 74% with respect to the unmodified PU. The 3D printed BN/PU composite scaffolds exhibit good biocompatibility and cell attachment enhancement with L929 fibroblast cells.

No abstract

No abstract

Heat sink can effectively dissipate heat in a range of thermal applications for improved performance and reliability. Thermally conductive polymer composites show great promise in solving the overheating issue in electronic devices. This experimental study investigates the thermal performance and the flow characteristics of straight and oblique finned heat sinks made of thermally conductive polymer composites under forced convection conditions over 7.45 × 10 4 ≤ Re ≤ 3.60 × 10 5 , where Re is the Reynolds number. The heat sinks used were 3D printed using Ice9 Flex (carbon filled polymer, from TCPoly), copper filled filament (polylactic acid with 80% copper particles) and bronze filled filament (polylactic acid with 80% bronze particles), respectively. Oblique fins were found to effectively reduce the thermal resistance of heat sinks, increase the convective heat transfer and the inner-fin velocity which results in lower pressure drop, in comparison to straight finned heat sinks. The carbon-filled polymer (Ice9 Flex) was shown to have much superior thermal dissipation characteristics compared to metal filled filaments.

No abstract