Dr. Juan Pablo Padilla-Martinez Profile

Dr. Juan Pablo Padilla-Martinez

Research Professor

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Publications (10)

SPIE Journal Paper | 21 July 2023 Open Access

Bubble dynamics and speed of jets for needle-free injections produced by thermocavitation

Nancy Elizabeth González-Sierra, José Manuel Perez-Corte, Juan Pablo Padilla-Martinez, Samuel Cruz-Vanegas, Silvio Bonfadini, Filippo Storti, Luigino Criante, Rubén Ramos-García

JBO, Vol. 28, Issue 07, 075004, (July 2023) https://doi.org/10.1117/12.10.1117/1.JBO.28.7.075004

KEYWORDS: Bubbles, Skin, Vacuum chambers, Liquids, Nozzles, Pulsed laser operation, Beam diameter, Design and modelling, Laser applications, Water

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SignificanceThe number of injections administered has increased dramatically worldwide due to vaccination campaigns following the COVID-19 pandemic, creating a problem of disposing of syringes and needles. Accidental needle sticks occur among medical and cleaning staff, exposing them to highly contagious diseases, such as hepatitis and human immunodeficiency virus. In addition, needle phobia may prevent adequate treatment. To overcome these problems, we propose a needle-free injector based on thermocavitation.AimExperimentally study the dynamics of vapor bubbles produced by thermocavitation inside a fully buried 3D fused silica chamber and the resulting high-speed jets emerging through a small nozzle made at the top of it. The injected volume can range from ∼0.1 to 2 μL per shot. We also demonstrate that these jets have the ability to penetrate agar skin phantoms and ex-vivo porcine skin.ApproachThrough the use of a high-speed camera, the dynamics of liquid jets ejected from a microfluidic device were studied. Thermocavitation bubbles are generated by a continuous wave laser (1064 nm). The 3D chamber was fabricated by ultra-short pulse laser-assisted chemical etching. Penetration tests are conducted using agar gels (1%, 1.25%, 1.5%, 1.75%, and 2% concentrations) and porcine tissue as a model for human skin.ResultHigh-speed camera video analysis showed that the average maximum bubble wall speed is about 10 to 25 m/s for almost any combination of pump laser parameters; however, a clever design of the chamber and nozzle enables one to obtain jets with an average speed of ∼70 m / s. The expelled volume per shot (0.1 to 2 μl) can be controlled by the pump laser intensity. Our injector can deliver up to 20 shots before chamber refill. Penetration of jets into agar of different concentrations and ex-vivo porcine skin is demonstrated.ConclusionsThe needle-free injectors based on thermocavitation may hold promise for commercial development, due to their cost and compactness.

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Proceedings Article | 6 February 2017 Presentation + Paper

In vivo assessment of wound re-epithelialization by UV fluorescence excitation imaging

Ying Wang, Antonio Ortega-Martinez, Juan Pablo Padilla-Martinez, Maura Williams, William Farinelli, R. Anderson, Walfre Franco

Proceedings Volume 10037, 100370R (2017) https://doi.org/10.1117/12.2253934

KEYWORDS: Wound healing, In vivo imaging, Skin, Image processing, Cell mechanics, Visualization, Fluorescent proteins, Tissues, Imaging systems

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Proceedings Article | 6 April 2016 Presentation + Paper

Statistical image segmentation for the detection of skin lesion borders in UV fluorescence excitation

Antonio Ortega-Martinez, Juan Pablo Padilla-Martinez, Walfre Franco

Proceedings Volume 9711, 97111B (2016) https://doi.org/10.1117/12.2208741

KEYWORDS: Image segmentation, Ultraviolet radiation, Ultraviolet photography, Skin, Photography, Image processing, Diagnostics, Image analysis, Interference (communication), Image processing algorithms and systems, Cameras, Wound healing

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Proceedings Article | 9 March 2016 Presentation + Paper

The endogenous fluorescence of fibroblast in collagen gels as indicator of stiffness of the extracellular matrix

J. P. Padilla-Martinez, A. Ortega-Martinez, W. Franco

Proceedings Volume 9710, 971005 (2016) https://doi.org/10.1117/12.2211184

KEYWORDS: Collagen, Tissues, Optical properties, Molecules, Ultraviolet radiation, Nondestructive evaluation, Tissue optics, Monochromators, Fluorescence spectroscopy, Fiber optics, Optical fibers, Statistical analysis

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Proceedings Article | 7 March 2016 Presentation + Paper

Preliminary investigation of intrinsic UV fluorescence spectroscopic changes associated with proteolytic digestion of bovine articular cartilage

William Lewis, Juan-Pablo Padilla-Martinez, Antonio Ortega-Martinez, Walfre Franco

Proceedings Volume 9703, 97031B (2016) https://doi.org/10.1117/12.2212932

KEYWORDS: Cartilage, Ultraviolet radiation, Luminescence, Spectroscopy, Fluorescence spectroscopy, Collagen, Mechanics, Biochemistry, Tissue optics, Matrices

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Proceedings Article | 15 March 2013 Paper

Liquid jet generated by thermocavitation bubbles within a droplet

J. Padilla-Martinez, Darren Banks, J. Ramirez-San-Juan, G. Aguilar, R. Ramos-Garcia

Proceedings Volume 8611, 86111J (2013) https://doi.org/10.1117/12.2004686

KEYWORDS: Liquids, Cavitation, Continuous wave operation, Glasses, Acoustics, Wave propagation, Microscopes, Video, Copper, Interfaces

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Proceedings Article | 26 October 2011 Paper

Thermocavitation as a tool for stratum corneum permeation

J. P. Padilla-Martínez, J. Ramírez-San-Juan, R. Ramos-García, F. Sun, G. Aguilar

Proceedings Volume 8011, 80112Z (2011) https://doi.org/10.1117/12.901583

KEYWORDS: Cavitation, Tissues, Breast, Microscopes, Continuous wave operation, Liquids, Video, Solids, Pulsed laser operation, Copper

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Proceedings Article | 9 September 2011 Paper

Temporal evolution of thermocavitation bubbles using high speed video camera

J. Padilla-Martinez, G. Aguilar, J. Ramirez-San-Juan, R. Ramos-García

Proceedings Volume 8097, 809727 (2011) https://doi.org/10.1117/12.894467

KEYWORDS: Cavitation, Video, Cameras, Continuous wave operation, Absorption, High speed cameras, Explosives, Solids, Copper, Microscopes

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Proceedings Article | 28 August 2010 Paper

Thermocavitation and its application for fabrication of micron-sized holes on metallic and dielectric thin films

J. Ramirez-San-Juan, J. Padilla-Martinez, P. Zaca Moran, E. Aboytes-Rodriguez, A. Martinez-Cantón, R. Ramos-Garcia

Proceedings Volume 7762, 77621E (2010) https://doi.org/10.1117/12.861314

KEYWORDS: Cavitation, Thin films, Titanium, Dielectrics, Continuous wave operation, Pulsed laser operation, Laser ablation, Glasses, Light sources, Solids

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Proceedings Article | 19 May 2007 Paper

Optical fiber sensor for the measurement of the pH level using organic dyes deposited by the sol-gel process

Juan Pablo Padilla Martínez, Imelda Santiago Núñez, Georgina Beltrán Pérez, Juan Castillo Mixcóatl, Severino Muñoz Aguirre, Rodolfo Palomino Merino

Proceedings Volume 6422, 64220Z (2007) https://doi.org/10.1117/12.742279

KEYWORDS: Sensors, Optical fibers, Fiber optics sensors, Thin films, Rhodamine, Sol-gels, Carbon monoxide, Absorption, Coating, Light

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Showing 5 of 10 publications

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