Welcome to the Precision Mechatronics Lab at the University of Newcastle

We are multidisciplinary group of electrical engineers, mechanical engineers and physicists developing new mechatronic and robotic technologies for fabrication, imaging, and health care

Conferences

IEEE International Conference On Mechatronics – Loughborough, UK, March 15-17, 2023

IEEE International Conference On Mechatronics - Loughborough, UK, March 15-17, 2023. IEEE International Conference on Mechatronics 2023 (IEEE ICM 2023) continues a series of biennial conferences dedicated to recent and prospective developments in various fields [...]

Micromechatronic Systems at IFAC World Congress, 2020

Join us for the open track sessions on Modeling, Identification, Estimation and Control in Micromechatronic Systems, at IFAC World Congress 2020, in Berlin, Germany. Organizers: Prof Helon Vicente Hultmann Ayala, Pontifical Catholic University of Rio [...]

News

A/Prof Andrzej Sikora’s visit to PML

As part of the Marie Skłodowska-Curie Actions (MSCA) ENSIGN project, we were pleased to host A/Prof Andrzej Sikora from Wrocław University of Science and Technology, Poland. A leading expert in metrology, he shared invaluable expertise [...]

Fabricating Microneedles Using Pulsating Electrohydrodynamic Force

Associate Professor Yuen Yong and her research team at Griffith University have introduced an innovative method known as PIDES—pulsating in situ dried electro stretching—for fabricating microneedles. The method produces needles under 1 mm in length, [...]

Paszkal’s Visit to Newcastle

It has been a fun 3 months working and learning from Paszkal on CFD modelling using OpenFoam. We had also done some interesting experiments together in the lab and will continue our collaboration in the [...]

Seminars

Linlin Li: Tracking control of the scanner for high-speed scanning of the AFM

Date & Venue Tuesday, 04 February 2020, 04:00pm EF122 Abstract The Atomic Force Microscope (AFM) has emerged as an indispensable research tool in the development of nanoscience and nanotechnology. Piezoelectrically actuated nanopositioning stages are widely [...]

Daniel Martin Jimenez: Atomic Force Microscopy: From Liquid to Ultra-high Vacuum Environments

Date & Venue Monday, 10 February 2020, 10:00am EF122 AbstractThe atomic force microscope (AFM) is a versatile tool that can operate in contact or dynamic mode on metallic, semiconductor, insulator or biological samples in liquid, [...]

Harm Schepens: Ultrasonic Orthopaedic Implant Release

Date & Venue Wednesday, 11 December 2019, 02:00pm EF122 Abstract In order to recover from fractures suffered in the limbs, intramedullary (IM) rods are inserted into the bone marrow canal. When in place, the IM [...]

Publications

335 entries « ‹ 1 of 67 › »

T. A. Hoang, H. D. Vu, D. Ngo, N. L. Mai, C. Doan, D. K. Tran, Y. Xiao, B. Rehm, Y. K. Yong, V. T. Dau

Free-templated Microfabrication of Hydrogel Microneedles Using Electrohydrodynamic Technique for Transdermal Drug Delivery Conference

The 29th International Conference on Miniaturized Systems for Chemistry and Life Sciences - Micro-Total Analysis Systems (uTas), Adelaide, 2 - 6 November, 2025, 2025.

Abstract | BibTeX

@conference{Hoang2025,

title = {Free-templated Microfabrication of Hydrogel Microneedles Using Electrohydrodynamic Technique for Transdermal Drug Delivery},

author = {T. A. Hoang, H. D. Vu, D. Ngo, N. L. Mai, C. Doan, D. K. Tran, Y. Xiao, B. Rehm, Y. K. Yong, V. T. Dau},

year = {2025},

date = {2025-11-03},

urldate = {2025-11-03},

booktitle = {The 29th International Conference on Miniaturized Systems for Chemistry and Life Sciences -

Micro-Total Analysis Systems (uTas)},

address = {Adelaide, 2 - 6 November, 2025},

abstract = {This study presents a template-free electrostreching microfabrication method for hydrogel microneedles, targeting applications in wound healing and drug delivery. Precursor solutions of gelatin methacryloyl (GelMa) and hyaluronic acid methacryloyl (HAMA) were subjected to a high-voltage electric field, forming a hydrogel microneedle structure by undergoing UV-crosslinking and solvent evaporation. The fabricated microneedles demonstrated optimal geometries, i.e., height-to-base ratios and the ability to be grown in parallel. In vitro cytotoxicity test confirmed the biocompatibility of the microneedles, as cells were able to adhere and proliferate on their surfaces.

Traditional transdermal drug delivery approaches, including hypodermic needles, topical creams, and transdermal patches, have significant drawbacks such as slow drug absorption and the painful and discomfort injection process [1], [2], [3]. Microneedles, which are arrays of micron-scale needles arranged in a small patch, offer an effective alternative solution by combining a non-invasive method and fast onset action to enhance patient compliance and potential for self-administration. Although there are various types of microneedles, most are fabricated using template-based methods such as moulding, lithography, or top-down micromachining, which require complicated processes in cleanroom facilities and limit design flexibility. To address these limitations, we report a template-free fabrication approach using electrohydrodynamic principles to produce microneedles directly on multiple substrate materials. Building upon prior work introduced in Small Methods [4], which focused on a proof-of-concept demonstration, this study extends the application to biocompatible hydrogels and evaluates the system’s scalability and safety for transdermal drug delivery. The method enables parallel microneedle fabrication and supports cell viability, highlighting its potential for practical therapeutic applications.

An overview of microneedle fabrication is illustrated in Figure 1. A hydrogel solution containing GelMa, HAMA, and the photo-initiator LAP (Lithium phenyl-2,4,6-trimethylbenzoylphosphinate) was prepared and dispensed as a droplet onto a substrate positioned between the two high-voltage electrodes. Under the applied pulsating electric field , the droplet was elongated and stretched into a conical shape (Taylor-cone shape). The droplet was then exposed to UV light to initiate hydrogel photo-polymerisation, which solidified the droplet’s outer layer. By the subsequent air-dry process, the solvent completely evaporates, resulting in a solid microneedle. This method enabled parallel microneedle formation, as shown in Figure 2, where five microneedles were simultaneously grown with consistent form and geometry. Figure 3 demonstrates the in-situ adaptability of the method, showcasing its ability to grow microneedles directly on various commercially available adhesive patches. GHMa-1, -2, and -3 samples exhibited desirable geometries, with height-to-base ratios from 1.90 to 3.23 (Table 1). Biocompatibility of the microneedle was validated by culturing cells (RAW 264.7) in direct contact with the microneedle, where cell adhesion and proliferation were observed (Figure 4). These findings underscore the potential of this technique for scalable and flexible fabrication of biocompatible hydrogel transdermal drug delivery platforms.},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

This study presents a template-free electrostreching microfabrication method for hydrogel microneedles, targeting applications in wound healing and drug delivery. Precursor solutions of gelatin methacryloyl (GelMa) and hyaluronic acid methacryloyl (HAMA) were subjected to a high-voltage electric field, forming a hydrogel microneedle structure by undergoing UV-crosslinking and solvent evaporation. The fabricated microneedles demonstrated optimal geometries, i.e., height-to-base ratios and the ability to be grown in parallel. In vitro cytotoxicity test confirmed the biocompatibility of the microneedles, as cells were able to adhere and proliferate on their surfaces.

Traditional transdermal drug delivery approaches, including hypodermic needles, topical creams, and transdermal patches, have significant drawbacks such as slow drug absorption and the painful and discomfort injection process [1], [2], [3]. Microneedles, which are arrays of micron-scale needles arranged in a small patch, offer an effective alternative solution by combining a non-invasive method and fast onset action to enhance patient compliance and potential for self-administration. Although there are various types of microneedles, most are fabricated using template-based methods such as moulding, lithography, or top-down micromachining, which require complicated processes in cleanroom facilities and limit design flexibility. To address these limitations, we report a template-free fabrication approach using electrohydrodynamic principles to produce microneedles directly on multiple substrate materials. Building upon prior work introduced in Small Methods [4], which focused on a proof-of-concept demonstration, this study extends the application to biocompatible hydrogels and evaluates the system’s scalability and safety for transdermal drug delivery. The method enables parallel microneedle fabrication and supports cell viability, highlighting its potential for practical therapeutic applications.

An overview of microneedle fabrication is illustrated in Figure 1. A hydrogel solution containing GelMa, HAMA, and the photo-initiator LAP (Lithium phenyl-2,4,6-trimethylbenzoylphosphinate) was prepared and dispensed as a droplet onto a substrate positioned between the two high-voltage electrodes. Under the applied pulsating electric field , the droplet was elongated and stretched into a conical shape (Taylor-cone shape). The droplet was then exposed to UV light to initiate hydrogel photo-polymerisation, which solidified the droplet’s outer layer. By the subsequent air-dry process, the solvent completely evaporates, resulting in a solid microneedle. This method enabled parallel microneedle formation, as shown in Figure 2, where five microneedles were simultaneously grown with consistent form and geometry. Figure 3 demonstrates the in-situ adaptability of the method, showcasing its ability to grow microneedles directly on various commercially available adhesive patches. GHMa-1, -2, and -3 samples exhibited desirable geometries, with height-to-base ratios from 1.90 to 3.23 (Table 1). Biocompatibility of the microneedle was validated by culturing cells (RAW 264.7) in direct contact with the microneedle, where cell adhesion and proliferation were observed (Figure 4). These findings underscore the potential of this technique for scalable and flexible fabrication of biocompatible hydrogel transdermal drug delivery platforms.

Free-templated Microfabrication of Hydrogel Microneedles Using Electrohydrodynamic Technique for Transdermal Drug Delivery

T. R. Young; Y. K. Yong; A. J. Fleming

Multivalve Configuration for Soft Robotics: Overcoming the Trade-Off Between Speed and Accuracy in Pneumatic Systems Journal Article

In: Robotics Reports, vol. 3, pp. 54-64, 2025.

Abstract | Links | BibTeX

Multivalve Configuration for Soft Robotics: Overcoming the Trade-Off Between Speed and Accuracy in Pneumatic Systems

M. Litman; S. Azarpeykan; R. J. Hood; K. Martin; D. Pepperall; D. Omileke; O. Uzun; D. Bhatta; Y. K. Yong; A. Chan; N. Hough; S. Johnson; P. G. Bermejo; F. Miteff; C. G. Esperon; Y. Couch; A. M. Buchan; N. J. Spratt; N. Korin; D. E. Ingber; D. J. Beard

Shear Stress Targeted Delivery of Nitroglycerin to Brain Collaterals Improves Ischaemic Stroke Outcome Journal Article

In: Advanced Science, vol. e06276, 2025.

Abstract | Links | BibTeX

@article{nokey,

title = {Shear Stress Targeted Delivery of Nitroglycerin to Brain Collaterals Improves Ischaemic Stroke Outcome},

author = {M. Litman and S. Azarpeykan and R. J. Hood and K. Martin and D. Pepperall and D. Omileke and O. Uzun and D. Bhatta and Y. K. Yong and A. Chan and N. Hough and S. Johnson and P. G. Bermejo and F. Miteff and C. G. Esperon and Y. Couch and A. M. Buchan and N. J. Spratt and N. Korin and D. E. Ingber and D. J. Beard},

doi = { https://doi.org/10.1002/advs.202506276},

year  = {2025},

date = {2025-08-13},

urldate = {2025-03-01},

journal = {Advanced Science},

volume = {e06276},

abstract = {In patients with ischaemic stroke, retrograde perfusion of the penumbra by the leptomeningeal collateral vessels (LMCs) is a strong predictor of clinical outcome, thus raising the possibility that enhancing LMC flow could offer a novel therapeutic approach. Here, using computational modelling we show that LMCs experience elevated fluid shear stress that is significantly higher than that in other blood vessels during ischaemic stroke in animals and humans. We take advantage of this to selectively enhance flow in LMCs using shear-activated nanoparticle aggregates carrying the vasodilator nitroglycerin (NG-NPAs) that specifically release drug in regions of vessels with high shear stress (≥100 dyne/cm2). The NG-NPAs significantly increased LMC-mediated penumbral perfusion, decreased infarct volume, and reduced neurological deficit without altering systemic blood pressure in a rat ischaemic stroke model. The NG-NPAs also did not cause known common side effects of systemic nitrate administration, such as systemic hypotension, cerebral vascular steal, cortical vein dilation, or intracranial pressure elevation. Systemic administration of free NG at the maximal tolerated dose, which was ten times higher than the dose of NG used in the NG-NPAs, did not enhance LMC perfusion and dropped blood pressure. Thus, packaging NG within shear-activated NPAs can potentially enable this widely available vasodilator to become a highly effective therapeutic for ischaemic stroke.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

Shear Stress Targeted Delivery of Nitroglycerin to Brain Collaterals Improves Ischaemic Stroke Outcome

Y. K. Yong; B. S. Routley; A. J. Fleming

Electromagnetic Objective Lens Scanner: Design, Modeling and Characterization Best Paper Proceedings Article

In: 2025, (Best Conference Paper Award).

Abstract | Links | BibTeX

Electromagnetic Objective Lens Scanner: Design, Modeling and Characterization

N. L. Mai, Y. K. Yong, T. A. Hoang, T. H. Vu, H Vu, V. C. Doan, D. Cai, T. X. Dinh, D. V. Dao, V. T. Dau

Fabrication of Microneedles by Pulsating In Situ Dried Electrostretching for Transdermal Drug Delivery Journal Article

In: Small Methods, vol. 9, pp. 2500183, 2025, (The paper's cover art has been selected as the frontispiece of the journal, Oct 2025).

Abstract | Links | BibTeX

Fabrication of Microneedles by Pulsating In Situ Dried Electrostretching for Transdermal Drug Delivery

335 entries « ‹ 1 of 67 › »

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Welcome to the Precision Mechatronics Lab at the University of Newcastle

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