Research

Additive manufacturing methods/processes

1. Dropwise digital printing of metals

State-of-the-art metal AM methods involve layer-by-layer deposition and selective binding or melting of metal powders. However, these methods do not easily permit multi-material printing or printing directly onto existing objects, and typically produce near-net-shape parts with poor dimensional resolution and surface finish unless extensive post-processing is applied. Here, we developed several direct metal printing routes with micron to millimeter size molten metal droplets (e.g. stainless steel, Cu, Ni, Al, Ti and their alloys, etc.), aiming to decouple the mass and energy transportation in traditional metal melting and deposition processes and achieve “voxel” printing of metals.

Selected publications:

[1] H. Merrow, J. Beroz, K. Zhang, U. Muecke, A.J. Hart, Digital metal printing by electrohydrodynamic ejection and in-flight melting of microparticles, Additive Manufacturing, 37, 101703, 2021.

[2] Liquid metal ejection printing, US Patent, 17/616,882, 2022.

2. Direct writing of carbon nanomaterials

We developed several laser direct writing processes for in-situ synthesis of few-layer graphene and 3D porous laser induced graphene (LIG) onto metallic and dielectric surfaces. We aim to bridge the gap between lab-level defect-free 2D material growth and real-world applications with carbon nanomaterials at multiple length scales.

Selected publications:

[1] K. Zhang, Transfer printing of metal films, Transfer printing technologies and applications, Elsevier, p369-418, 2024.

[2] K. Zhang* and A.J. Hart*, Interfacial chemical vapor deposition of wrinkle-free bilayer graphene on dielectric substrates, Applied Surface Science, 602, 154367, 2022.

3. Process-structure-property integration in metal AM

•Fluid mechanics and heat/mass transport in L-PBF and DED processes

•Microstructure control and characterization in metal AM

Selected publications:

Coming soon…

Metal matrix composites(MMCs)

1. Fabrication of MMCs

•Additive manufacturing of MMCs

•Configuration design and control for high performance MMCs

Selected publications:

[1] K. Zhang, C. Androulidakis, M. Chen, S. Tawfick*, Gilding with graphene: rapid chemical vapor deposition synthesis of graphene on thin metal leaves, Advanced Functional Materials, 28(48), 2018.

2. Micro/nano-mechanics in MMCs

•Interface engineering

•Thin film mechanics

•Strengthening and toughening

Selected publications:

[1] K. Zhang, M. Surana, J. Yaacoub, S. Tawfick*, Ultrathin damage-tolerant flexible metal interconnects reinforced by in-situ graphene synthesis, npj Flexible Electronics, 8(1), 2024.

[2] M. Surana, G. Ananthakrishnan, M. Poss, J. Yaacoub, K. Zhang, et al., Strain-driven faceting of graphene-catalyst interfaces, Nano Letters, 23(5), 2023.

[3] K. Zhang, M. Surana, R. Haasch, S. Tawfick*, Elastic modulus scaling in graphene-metal composite nanoribbons, Journal of Physics D: Applied Physics, 53(18), 2020.

[4] K. Zhang, M. Poss, P. Chen, S. Tawfick*, Strengthening nickel by in situ graphene synthesis, Advanced Engineering Materials, 19: 1700475, 2017.

The synergy between advanced manufacturing and other critical technologies

1. Thermal management solutions for high heat flux electronics

•Liquid cold plate by metal additive manufacturing

•Topology optimization for high efficiency heat exchanging

•Digital light processing (DLP) of ultrafine metallic structures for microchannel heat exchangers/reactors

Selected publications:

Coming soon…

2. Advanced materials and manufacturing for human computer interaction

We collaborate with researchers in Computational Media and Arts (CMA) field on applying advanced materials and advanced manufacturing techniques in human computer interaction (HCI). Currently, we are focusing on:

•Haptic sensing

•Haptic rendering

•3D printed electronics