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Thickness measurement of polymer thin films with high frequency ultrasonic transducers (2019)
Presentation / Conference Contribution
Smith, R. J., Cavera, S. L., Pérez-Cota, F., Marques, L., & Clark, M. (2018, July). Thickness measurement of polymer thin films with high frequency ultrasonic transducers. Presented at 45th Annual Review of Progress in Quantitative Nondestructive Evaluation, Vermont, USA

© 2019 Author(s). In this paper we present a method for characterizing the thickness, and more interestingly, the variation of thickness in polymer thin films (<1 µm). The technique utilizes an optoacoustic transducer atop the polymer film; as the tr...

New insights into the mechanical properties of Acanthamoeba castellanii cysts as revealed by phonon microscopy (2019)
Journal Article
Pérez-Cota, F., Smith, R. J., Elsheikha, H. M., & Clark, M. (2019). New insights into the mechanical properties of Acanthamoeba castellanii cysts as revealed by phonon microscopy. Biomedical Optics Express, 10(5), 2399-2408. https://doi.org/10.1364/BOE.10.002399

The single cell eukaryotic protozoan Acanthamoeba castellanii exhibits a remarkable ability to switch from a vegetative trophozoite stage to a cystic form, in response to stressors. This phenotypic switch involves changes in gene expression and synth... Read More about New insights into the mechanical properties of Acanthamoeba castellanii cysts as revealed by phonon microscopy.

Super-resolution imaging using nano-bells (2018)
Journal Article
Fuentes-Dominguez, R., Pérez-Cota, F., Naznin, S., Smith, R. J., & Clark, M. (2018). Super-resolution imaging using nano-bells. Scientific Reports, 8, 1-9. https://doi.org/10.1038/s41598-018-34744-6

In this paper we demonstrate a new scheme for optical super-resolution, inspired, in-part, by PALM and STORM. In this scheme each object in the field of view is tagged with a signal that allows them to be detected separately. By doing this we can ide... Read More about Super-resolution imaging using nano-bells.

Non destructive evaluation of biological cells (2018)
Presentation / Conference Contribution
Pérez-Cota, F., Smith, R. J., Moradi, E., Webb, K. F., & Clark, M. (2019). Non destructive evaluation of biological cells. AIP Conference Proceedings, 2102, https://doi.org/10.1063/1.5099737

© 2019 Author(s). Regenerative medicine promises to be the next revolution in health care. This technology, which will be the first systematic manufacturing of biological parts for human consumption, requires non destructive evaluatioin (NDE) thechni... Read More about Non destructive evaluation of biological cells.

Active chiral control of GHz acoustic whispering-gallery modes (2017)
Journal Article
Mezil, S., Fujita, K., Osuka, P. H., Tomoda, M., Clark, M., Wright, O. B., & Matsuda, O. (in press). Active chiral control of GHz acoustic whispering-gallery modes. Applied Physics Letters, https://doi.org/10.1063/1.4994886

We selectively generate chiral surface-acoustic whispering gallery modes in the gigahertz range on a microscopic disk by means of an ultrafast time-domain technique incorporating a spatial light modulator. Active chiral control is achieved by making... Read More about Active chiral control of GHz acoustic whispering-gallery modes.

Enhanced sensing and conversion of ultrasonic Rayleigh waves by elastic metasurfaces (2017)
Journal Article
Colombi, A., Ageeva, V., Smith, R. J., Clare, A. T., Patel, R., Clark, M., …Craster, R. V. (2017). Enhanced sensing and conversion of ultrasonic Rayleigh waves by elastic metasurfaces. Scientific Reports, 7(1), Article 6750. https://doi.org/10.1038/s41598-017-07151-6

Recent years have heralded the introduction of metasurfaces that advantageously combine the vision of sub-wavelength wave manipulation, with the design, fabrication and size advantages associated with surface excitation. An important topic within met... Read More about Enhanced sensing and conversion of ultrasonic Rayleigh waves by elastic metasurfaces.

Orientation imaging of macro-sized polysilicon grains on wafers using spatially resolved acoustic spectroscopy (2017)
Journal Article
Patel, R., Li, W., Smith, R. J., Sharples, S. D., & Clark, M. (2017). Orientation imaging of macro-sized polysilicon grains on wafers using spatially resolved acoustic spectroscopy. Scripta Materialia, 140, 67-70. https://doi.org/10.1016/j.scriptamat.2017.07.003

Due to its economical production process polysilicon, or multicrystalline silicon, is widely used to produce solar cell wafers. However, the conversion efficiencies are often lower than equivalent monocrystalline or thin film cells, with the structur... Read More about Orientation imaging of macro-sized polysilicon grains on wafers using spatially resolved acoustic spectroscopy.

Facile approach to generating polymeric nanoarrays containing populations of nanoparticles (2015)
Journal Article
Marques, L., Chen, X., Roberts, C. J., Clark, M., & Aylott, J. W. (2015). Facile approach to generating polymeric nanoarrays containing populations of nanoparticles. Micro and Nano Letters, 10(8), 378-383. https://doi.org/10.1049/mnl.2015.0041

The production of nanoarrays containing a population of entrapped, heterogeneous nanoparticles is reported. The nanoarray consists of a nanoporous film with pores of diameter 60-180 nm, formed from the phase separation of two immiscible polymers: pol... Read More about Facile approach to generating polymeric nanoarrays containing populations of nanoparticles.

Spatially resolved acoustic spectroscopy for rapid imaging of material microstructure and grain orientation (2014)
Journal Article
Smith, R. J., Li, W., Coulson, J., Clark, M., Somekh, M. G., & Sharples, S. D. (2014). Spatially resolved acoustic spectroscopy for rapid imaging of material microstructure and grain orientation. Measurement Science and Technology, 25(5), Article 055902. https://doi.org/10.1088/0957-0233/25/5/055902

Measuring the grain structure of aerospace materials is very important to understand their mechanical properties and in-service performance. Spatially resolved acoustic spectroscopy is an acoustic technique utilizing surface acoustic waves to map the... Read More about Spatially resolved acoustic spectroscopy for rapid imaging of material microstructure and grain orientation.

Sound of nano (2013)
Presentation / Conference Contribution
Aylott, J., Clark, M., Marques, L., Perez-Cota, F., Smith, R. J., & Webb, K. F. (2013). Sound of nano. Proceedings of SPIE, 8923, Article 892325. https://doi.org/10.1117/12.2035176

Ultrasound is widely used for imaging, measurement and diagnostics in the MHz region and is perhaps most familiar as a medical or non-destructive imaging or measurement tool. In the MHz frequency range the wavelength is typically measured in microns... Read More about Sound of nano.

Widefield ultrastable heterodyne interferometry using a custom CMOS modulated light camera (2011)
Presentation / Conference Contribution
Patel, R., Clark, M., & Achamfuo-Yeboah, S. (2011). Widefield ultrastable heterodyne interferometry using a custom CMOS modulated light camera.

A method of detecting optical heterodyne interference fringes using a custom CMOS modulated light camera array has been developed. Widefield phase images are generated using quadrature demodulation and are kept stable using a feedback system.
© 2011... Read More about Widefield ultrastable heterodyne interferometry using a custom CMOS modulated light camera.

The design and characterisation of an optical VLSI processor for real time centroid detection (2002)
Journal Article
Pui, B. H., Hayes-Gill, B., Clark, M., Somekh, M., See, C., Piéri, J. F., …Ng, A. (2002). The design and characterisation of an optical VLSI processor for real time centroid detection. Analog Integrated Circuits and Signal Processing, 32(1), 67-75. https://doi.org/10.1023/A%3A1016075825331

The integration of photo-detectors onto a standard CMOS integrated circuit is presented. This device provides the optical front end for a real time centroid detection system to be used as part of a larger system for implementing a Shack-Hartmann wave... Read More about The design and characterisation of an optical VLSI processor for real time centroid detection.

The Design of a Real Time VLSI Optical Centroid Processor (2002)
Presentation / Conference Contribution
Pui, B. H., Hayes-Gill, B., Clark, M., Somekh, M., See, C., Morgan, S., & Ng, A. (2002). The Design of a Real Time VLSI Optical Centroid Processor. In IEEE Sensors 2002 : first IEEE International Conference on Sensors. https://doi.org/10.1109/ICSENS.2002.1036977

A real time VLSI optical centroid processor has been developed as part of a larger Shack-Hartmann wavefront sensor system for applications in adaptive optics. The implementation of the optical centroid detection system was demonstrated successfully u... Read More about The Design of a Real Time VLSI Optical Centroid Processor.