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Administering medicine to preventing forgery: The potential of joint India-Australia research

Researchers from Sydney and Bombay have developed novel 3D-metastructures at nanoscale to produce solutions to a diverse range of challenges.

Overview

Today’s smartwatches, ultrabooks and powerful supercomputers are made possible by the extreme miniaturisation achieved through advanced microfabrication. The newly emerging nanofabrication tools will take these technologies one step further: enabling construction of super-fine features at higher density to produce devices that are lightweight and super-compact with greater affordability.

Researchers from The University of Sydney (USYD, Australia), led by Dr Vincent Gomes, and The Indian Institute of Technology, Bombay (IITB, India), led by Dr Shobha Shukla, have developed novel 3D-metastructures at nanoscale for application in electronics, sensing and detection, advanced manufacturing and biomedicine.

Outcomes

The USyd-IITB team developed a state-of-the-art nanofabrication system for constructing structures that were formerly either extremely expensive or commercially infeasible. For instance, applying the conventional 3D additive manufacturing techniques, the generation of sub-micron structures can be accomplished by use of high-cost materials and fabrication tools with serial processing at speeds of about ~0.001 mm/s which result in final products that are unaffordable.

Researchers developed a novel composite system based on a commercially available photosensitive resin and non-toxic, eco-friendly, organic quantum dots. In conjunction with a femtosecond laser writing system, the system is able to achieve resolutions of less than 250 nm at writing speeds of 100 mm/s. This is a game-changer in the field of 3D additive manufacturing for nanostructured devices in terms of realisation of unprecedented speed and scale at affordable price points. The total exclusion of toxic materials in the process and fabrication of fluorescent metastructures add further value in producing biomedical devices for in vivo applications.

The team has successfully developed arrays of microneedle patches for transdermal drug delivery for painless injection of vaccines and regulated dose of medications such as insulin for diabetes. These structures are non-obtrusive and discreet due to their fabricated scale of 50 μm which is finer than the tip of a  strand of human hair. The team also developed a system to generate micro quick-response (μQR) codes for authentication and anti-counterfeiting measures, comprising layered security codes with unique fabrication parameters for facile readout at high magnification.

These breakthroughs herald paradigm shifts in the world of additive manufacturing for producing optically active devices for miniaturised lasers, sensing devices and biotherapeutics. For example, the microneedle system can be adapted as a point-of-care (POC) clinic-on-a-chip (COAC) with machine learning for on-demand transdermal drug delivery. It can exploit the multimodal behaviour of engineered quantum dots combined with monolithic integration of nanostructures over a single platform. The continuous monitoring of stimulus via sensor attached to the microneedle can enable transfer of appropriate response to the triggering electronics to facilitate on-demand drug delivery.

Image: Microneedle arrays (40μm high)  

Further information:

A. Jaiswal, S. Rani, G.P. Singh, M. Hassan, A. Nasrin, V.G. Gomes, S. Saxena, S. Shukla, Additive-Free All-Carbon Composite: A Two-Photon Material System for Nanopatterning of Fluorescent Sub-Wavelength Structures, ACS Nano, 15, 9, 14193–14206, 2021.

A. Jaiswal, S. Rani, G.P. Singh, M. Hassan, A. Nasrin, V.G. Gomes, S. Saxena, S. Shukla, Additive Manufacturing of Highly Fluorescent Organic 3D-Metastructures at Sub-Wavelength Resolution, Materials Today Physics, 20, 100434, 2021.

A. Jaiswal, S. Rani, M. Hassan, V.G. Gomes, S. Saxena, S. Shukla, Carbon Quantum Dots based Patternable Material System for Fabricating Fluorescent Nanostructures with Sub-wavelength Resolution, Patent Application 202221052488, 2022.