Advanced Materials & Nature Communications paper - Nanyang Asst Prof Hortense Le Ferrand

'Microstructured BN Composites with Internally Designed High Thermal Conductivity Paths for 3D Electronic Packaging' (published in Advanced Materials)

 

Miniaturized and high-power-density 3D electronic devices pose new challenges on thermal management. Indeed, prompt heat dissipation in electrically insulating packaging is currently limited by the thermal conductivity achieved by thermal interface materials (TIMs) and by their capability to direct the heat toward heat sinks. Here, high thermal conductivity boron nitride (BN)-based composites that are able to conduct heat intentionally toward specific areas by locally orienting magnetically functionalized BN microplatelets are created using magnetically assisted slip casting. The obtained thermal conductivity along the direction of alignment is unusually high, up to 12.1 W m⁻¹ K⁻¹, thanks to the high concentration of 62.6 vol% of BN in the composite, the low concentration in polymeric binder, and the high degree of alignment. The BN composites have a low density of 1.3 g cm⁻³, a high stiffness of 442.3 MPa, and are electrically insulating. Uniquely, the approach is demonstrated with proof-of-concept composites having locally graded orientations of BN microplatelets to direct the heat away from two vertically stacked heat sources. Rationally designing the microstructure of TIMs to direct heat strategically provides a promising solution for efficient thermal management in 3D integrated electronics. (DOI: https://doi.org/10.1002/adma.202205120)

 

Advanced Materials is a weekly peer-reviewed scientific journal covering materials science. It includes communications, reviews, and feature articles on topics in chemistry, physics, nanotechnology, ceramics, metallurgy, and biomaterials. According to the Journal Citation Reports, the journal has a 2021 impact factor of 32.086.

'Magnetically assisted drop-on-demand 3D printing of microstructured multimaterial composites' (published in Nature Communications)

 

Microstructured composites with hierarchically arranged fillers fabricated by three-dimensional (3D) printing show enhanced properties along the fillers’ alignment direction. However, it is still challenging to achieve good control of the filler arrangement and high filler concentration simultaneously, which limits the printed material’s properties. In this study, we develop a magnetically assisted drop-on-demand 3D printing technique (MDOD) to print aligned microplatelet reinforced composites. By performing drop-on-demand printing using aqueous slurry inks while applying an external magnetic field, MDOD can print composites with microplatelet fillers aligned at set angles with high filler concentrations up to 50 vol%. Moreover, MDOD allows multimaterial printing with voxelated control. We showcase the capabilities of MDOD by printing multimaterial piezoresistive sensors with tunable performances based on the local microstructure and composition. MDOD thus creates a large design space to enhance the mechanical and functional properties of 3D printed electronic or sensing devices using a wide range of materials. (DOI: https://doi.org/10.1038/s41467-022-32792-1)

 

Nature Communications is an open access, multidisciplinary journal dedicated to publishing high-quality research in all areas of the biological, health, physical, chemical and Earth sciences. Papers published by the journal aim to represent important advances of significance to specialists within each field. The journal has a 2021 impact factor of 17.694.

 

Our heartiest congratulations to Asst/P Hortense Le Ferrand and her team on their publications in the top-tier scientific journals.