Proceedings of SPIE - The International Society for Optical Engineering, 2011
Microfluidic systems have faced challenges in handling real samples and the chip interconnection ... more Microfluidic systems have faced challenges in handling real samples and the chip interconnection to other instruments. Here we present a simple interface, where surface acoustic waves (SAWs) from a piezoelectric device are coupled into a disposable ...
IEEE Journal of Selected Topics in Quantum Electronics, 2004
We propose a novel type of semiconductor laser mode-locked by the Kerr-effect induced refractive ... more We propose a novel type of semiconductor laser mode-locked by the Kerr-effect induced refractive index change of a polymer. Such a device is shown to have the potential to produce dramatically shorter pulses than those devices currently in use.
We have fabricated high-quality planar photonic crystal defect waveguides in InP/InGaAsP material... more We have fabricated high-quality planar photonic crystal defect waveguides in InP/InGaAsP material. Using Fourier analysis of the Fabry-Perot fringes obtained in transmission, we derive the propagation losses. Values as small as 1.8 dB/mm for waveguides consisting of 3 rows of missing holes ("W3") were measured. To the best of our knowledge, this is the smallest loss in III-V semiconductor photonic
... Thus, the selectivity of chemically overetched features lies above the balanced line and that... more ... Thus, the selectivity of chemically overetched features lies above the balanced line and that of chemically underetched (physically overetched) features lies below (Fig. ... We have also observed that the remaining silica mask after a CAIBE etch is more resis-tant to RIE than before ...
Soft ionization methods for the introduction of labile biomolecules into a mass spectrometer are ... more Soft ionization methods for the introduction of labile biomolecules into a mass spectrometer are of fundamental importance to biomolecular analysis. Previously, electrospray ionization (ESI) and matrix assisted laser desorption-ionization (MALDI) have been the main ionization methods used. Surface acoustic wave nebulization (SAWN) is a new technique that has been demonstrated to deposit less energy into ions upon ion formation and transfer for detection than other methods for sample introduction into a mass spectrometer (MS). Here we report the optimization and use of SAWN as a nebulization technique for the introduction of samples from a low flow of liquid, and the interfacing of SAWN with liquid chromatographic separation (LC) for the analysis of a protein digest. This demonstrates that SAWN can be a viable, low-energy alternative to ESI for the LC-MS analysis of proteomic samples.
A quantity of silver was evaporated onto platinised-silicon (Pt/Ti/SiO2/Si) and then annealed in ... more A quantity of silver was evaporated onto platinised-silicon (Pt/Ti/SiO2/Si) and then annealed in air to form a silver-platinum alloy. The lattice spacing of the alloy matched that of the composition of lead zirconate titanate (PZT) used. The surface of the silver-platinum alloy was covered in hillocks. It was found that after PZT was deposited by chemical solution deposition (CSD) these
We study the influence of acoustic fields on the evaporative self-assembly of solute particles su... more We study the influence of acoustic fields on the evaporative self-assembly of solute particles suspended inside sessile droplets of complex fluids. The self-assembly process often results in an undesirable ring-like heterogeneous residue, a phenomenon known as the coffee-ring effect. Here we show that this ring-like self-assembly can be controlled acoustically to form homogeneous disc-like or concentrated spot-like residues. The principle of our method lies in the formation of dynamic patterns of particles in acoustically excited droplets, which inhibits the evaporation-driven convective transport of particles towards the contact line. We elucidate the mechanisms of this pattern formation and also obtain conditions for the suppression of the coffee-ring effect. Our results provide a more general solution to suppress the coffee-ring effect without any physiochemical modification of the fluids, the particles or the surface, thus potentially useful in a broad range of industrial and an...
A study of the footprint created by the weathering of microbial habitat in a Mars analogue enviro... more A study of the footprint created by the weathering of microbial habitat in a Mars analogue environment.
Proceedings of SPIE - The International Society for Optical Engineering, 2011
Microfluidic systems have faced challenges in handling real samples and the chip interconnection ... more Microfluidic systems have faced challenges in handling real samples and the chip interconnection to other instruments. Here we present a simple interface, where surface acoustic waves (SAWs) from a piezoelectric device are coupled into a disposable ...
IEEE Journal of Selected Topics in Quantum Electronics, 2004
We propose a novel type of semiconductor laser mode-locked by the Kerr-effect induced refractive ... more We propose a novel type of semiconductor laser mode-locked by the Kerr-effect induced refractive index change of a polymer. Such a device is shown to have the potential to produce dramatically shorter pulses than those devices currently in use.
We have fabricated high-quality planar photonic crystal defect waveguides in InP/InGaAsP material... more We have fabricated high-quality planar photonic crystal defect waveguides in InP/InGaAsP material. Using Fourier analysis of the Fabry-Perot fringes obtained in transmission, we derive the propagation losses. Values as small as 1.8 dB/mm for waveguides consisting of 3 rows of missing holes ("W3") were measured. To the best of our knowledge, this is the smallest loss in III-V semiconductor photonic
... Thus, the selectivity of chemically overetched features lies above the balanced line and that... more ... Thus, the selectivity of chemically overetched features lies above the balanced line and that of chemically underetched (physically overetched) features lies below (Fig. ... We have also observed that the remaining silica mask after a CAIBE etch is more resis-tant to RIE than before ...
Soft ionization methods for the introduction of labile biomolecules into a mass spectrometer are ... more Soft ionization methods for the introduction of labile biomolecules into a mass spectrometer are of fundamental importance to biomolecular analysis. Previously, electrospray ionization (ESI) and matrix assisted laser desorption-ionization (MALDI) have been the main ionization methods used. Surface acoustic wave nebulization (SAWN) is a new technique that has been demonstrated to deposit less energy into ions upon ion formation and transfer for detection than other methods for sample introduction into a mass spectrometer (MS). Here we report the optimization and use of SAWN as a nebulization technique for the introduction of samples from a low flow of liquid, and the interfacing of SAWN with liquid chromatographic separation (LC) for the analysis of a protein digest. This demonstrates that SAWN can be a viable, low-energy alternative to ESI for the LC-MS analysis of proteomic samples.
A quantity of silver was evaporated onto platinised-silicon (Pt/Ti/SiO2/Si) and then annealed in ... more A quantity of silver was evaporated onto platinised-silicon (Pt/Ti/SiO2/Si) and then annealed in air to form a silver-platinum alloy. The lattice spacing of the alloy matched that of the composition of lead zirconate titanate (PZT) used. The surface of the silver-platinum alloy was covered in hillocks. It was found that after PZT was deposited by chemical solution deposition (CSD) these
We study the influence of acoustic fields on the evaporative self-assembly of solute particles su... more We study the influence of acoustic fields on the evaporative self-assembly of solute particles suspended inside sessile droplets of complex fluids. The self-assembly process often results in an undesirable ring-like heterogeneous residue, a phenomenon known as the coffee-ring effect. Here we show that this ring-like self-assembly can be controlled acoustically to form homogeneous disc-like or concentrated spot-like residues. The principle of our method lies in the formation of dynamic patterns of particles in acoustically excited droplets, which inhibits the evaporation-driven convective transport of particles towards the contact line. We elucidate the mechanisms of this pattern formation and also obtain conditions for the suppression of the coffee-ring effect. Our results provide a more general solution to suppress the coffee-ring effect without any physiochemical modification of the fluids, the particles or the surface, thus potentially useful in a broad range of industrial and an...
A study of the footprint created by the weathering of microbial habitat in a Mars analogue enviro... more A study of the footprint created by the weathering of microbial habitat in a Mars analogue environment.
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