Next Generation Inkjet Technology, Feb 2007-Aug 2009, EPSRC, grant GR/T11920
Realising the Potential of Next Generation Printed Pharmaceuticals, Oct 2009-March 2012, TSB
Innovation in Industrial Inkjet Technology – I4T, April 2012 – July 2015, EPSRC, grant EP/H018913/1
Inca Digital Consultancy: inkjet printing, July 2014 – July 2015
Inca Digital/DU Inkjet Printing Project, Aug 2015 – present
P&G/DU Droplet Impact, Splashing and Drainage in Automatic Dishwashers, Jan 2016 – present
Research – Outline
My research work in Prof. Bain’s group is focusing on developing techniques on characterising dynamic properties of fluid (drops, jets and film) and understanding the link between microscopic structure of the fluid and macroscopic behavior of drop/film. The fundamental research would benefit to the inkjet printing industries and beyond.
Research – A Closer Look
Liquid microjet: we developed a new approach to the study of instabilities in liquid microjet by confocal imaging. The achievable spatial resolution of 4 nm in the perturbed jet is superior to conventional methods. The method has been applied to measure dynamic surface tension of solvent mixtures and surfactant solutions at surface age of ≤ 1 ms.
Liquid microdrop: we collaborated with Cambridge university applied the oscillating droplet method to drops that are formed in manufacturing processes involving nozzles or jets for a direct measurement of transient shear viscosity and dynamic surface tension of both pure and complex fluid.
Satellite control: we collaborated with GlaxoSmithKline (GSK) and Leeds University and extended the technique to printing pharmaceutical suspensions onto the placebo tablet. We developed a strategy to fine control satellite formation of microlitre drops which has been adapted in GSK production pilot line.
Drop deposition:we applied 2D particle image velocimetry (PIV) to measure the internal flows of pL- drying droplet and developed a strategy to control the deposition of solvent-based droplets via a gelator with specific non-Newtonian property
Image analysis: we developed a package (Matlab GUI) of image analysis to study dynamics of droplets through formation, oscillation, impact, spreading and deposition via drop morphology
We collaborated with Inca digital and developed a visualisation system for the industrial printhead to monitor real-time printing process
We developed holographic interferometry for surface profiling with resolution of 20 nm which is suitable for the characterisation of pL-drop deposition
We are currently developing holographic particle tracking velocimetry (PTV) to study internal flow of pL-droplet drying, and thin film drainage.
E.L. Talbott, H.N. Yow, L.S. Yang, A. Berson, S.R. Biggs, C.D. Bain "Printing Small Dots from Large Drops" ACS Applied Materials and Interfaces 2015, 7, 3782-3790 (DOI)
L. Yang, B.K. Kazmierski, S.D. Hoath, S. Jung, W. Hsiao, Y. Wang, A. Berson, O. Harlen, N. Kapur and C.D. Bain "Determination of dynamic surface tension and viscosity of non-Newtonian fluids from drop oscillations" Physics of Fluids 2014, 26 (DOI)
E.L. Talbot, L.S. Yang, A Berson, C.D. Bain "Control of the Particle Distribution in Inkjet Printing through an Evaporation-Driven Sol-Gel Transition" Applied Materials & Interfaces 2014, 6, 9572-9583 (DOI)
L. Yang, C. D. Bain "Study of Liquid Jet Instability by Confocal Microscopy" Rev. Sci. Instr. 2012, 073104 (DOI)
E. L. Talbot, A. Berson, L. Yang and C. D. Bain, “Internal Flows and Particle Transport Inside Picoliter Droplets of Binary Solvent Mixtures”, NIP29 Digital printing technologies conference, USA (2013)
L. Yang and C. D. Bain, “Liquid jet instability and dynamic surface tension effect on breakup”, NIP25 Digital printing technologies conference in Louisville KY, 79-82, USA (2009)
L. Yang, N. Kapur, Yiwei Wang, Fritz Fiesser, Frank Bierbrauer, Mark Wilson, Tim Sabey and C. D. Colin. “Drop-on-demand satellite free drop formation – a precision fluid delivery”, in draft, 2016
L. Yang, A. Mac Raighne, E. M. McCabe, L. A. Dunbar, and T. Scharf, “Confocal microscopy using variable-focal-length microlenses and optical fiber bundle”, Appl. Opt. 44(28), 5928-5936(2005)
L. Yang, C. Taylor, Y. Rakovich, and E. McCabe, “The three-dimensional imaging of microspheres with confocal and conventional polarization microscopes”, Appl. Opt. 42(28), 5693-5700 (2003)
Y. P. Rakovich, L. Yang, E. M. McCabe, J. F. Donegan, T. Perova, A. Moore, N. Gaponik & A. Rogach, “Whispering gallery mode emission from a composite system of CdTe nanocrystals and spherical microcavity,” Semicond Sci Technol, 18(11), 914–918 (2003)
L. Yang, G. Wang, J.Wang, G. Wang and Z. Xu, “Spectroscopic properties of azo-dye doped PMMA films studied by multi-photon excitation,” Optik 113(4), 189-191 (2002)
L. Yang, L. Liu, G. Wang and Z. Xu, “Non-interferometric measurement of PZT converse piezoelectric extension,” Opt. Eng. 40(6), 909-913 (2001)
L. Yang, G. Wang, J. Wang and Z. Xu, “Surface profilometry with fiber optical confocal scanning microscope,” Meas. Sci. & Techn. (Formerly: J. Physics E), 11(12), 1786-1791 (2000)
L. Liu, X. Deng, L. Yang, G. Wang, and Zh. Xu, “Effect of the annular pupil filter on the differential confocal microscopy”, Opt. Lett. 25(23), 1711-1713 (2000)
L. Yang, G. Wang, J. Wang and Z. Xu, “Influence of fiber terminal face reflection on fiber optical confocal scanning microscope,” SPIE Proc. Vol. 3863, pp.332-336 (1999)
L. Yang, G. Wang, J. Wang, Y. Bu,and Zh. Xu, “Research on refection-mode fiber-optical scanning imaging system,” Acta Optica Sinica (in Chinese), 19(7), 962-967 (1999)
L. Yang, G. Wang, J. Wang, and Zh. Xu, “Fiber confocal scanning microscopy for the measurement of optical disk pregrooves,” Acta Optica Sinica (in Chinese), 20(3), 384-388 (2000)
L. Yang, Zh. Wang, G. Wang, and Zh. Xu, “Focusing of femtosecond Gaussian beam by lenses,” Chinese J. Lasers A (in Chinese), 28(6), 518-522 (2001)
Clarke, A., Fiesser, F., Yang, L., Bain, C. D. & Kapur, N. 2013 Liquid dispensing device and methods of control the same. Patent application 61/790508.2013
L. Yang, G. Wang and Zh. Xu, A new profilometry by confocal scanning microscopy, Chinese patent No. CN99113699.3 (November 2000)
G. Wang, L. Yang, and Zh. Xu, Fiber confocal scanning microscope with a survey eyepiece, Chinese patent No. CN99113633.0 (October 2000)
G. Wang, L. Yang, and Zh. Xu, Fiber confocal scanning microscope, Chinese patent, No. CN99240337.5 (September 2000)
Working in Colin’s group is an adventure of the mind and a journey towards the understanding of nature. Back home, I am by and large a responsible mother of two sons and always enjoy good food, gardening and chat with friends. My favorite sports are table tennis, badminton and Chinese chess but hardly find companion at Durham.
I enjoy being a life-long learner. I seek simplicity and trust it!