AOT-100 AEROSOL OPTICAL TWEEZER
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AOT-100 Aerosol Optical Tweezer A major advance in the study of airborne particles AOT-100 OVERVIEW The AOT-100 allows users to hold airborne particles for extended periods with ease. Holding particles in an optical trap enables many different parameters to be studied continuously over times varying from milliseconds to hours. The AOT-100 is the result of a collaboration between the Bristol University Aerosol Research Centre and Biral. Prior to the AOT-100 aerosol instruments have mostly relied on transits through an illuminated measuring space that last of the order of microseconds. While this has enabled measurements to be made on very large numbers of particles it severely limits what can be measured and precludes the study of any time-dependent processes. By trapping particles in the focus of a laser beam the dynamic processes that are vital to the understanding the relationship between particles and the medium in which they are suspended become feasible. Aerosols play a vital role in many processes and studying their evolution with time is vital to developing a detailed understanding of fields as diverse as climate change and drug delivery to the lungs. BRISTOL INDUSTRIAL AND RESEARCH ASSOCIATES LIMITED Telephone : +44 (0)1275 847787 Facsimile : +44(0)1275 847303 E-mail: info@biral.com Home Page at http://www.biral.com

The ability to trap multiple particles and move them within the cell by the use of a Spatial Light Modulator (SLM). A measurement cell that enables particles to be trapped and manipulated in a controlled environment. Precise measurement of particle size and refractive index. Single particle Ramen spectroscopy. Measurements can be made over periods ranging from milliseconds to hours or days. A 532nm trapping laser. Wavelength selected to minimise absorption by aqueous droplets. An optical system that creates a very tightly focussed beam and so a strong trap within the cell space. Particle...

Instrument Design The system is based on the research instrument designs developed by Professor Reid’s Aerosol Research Centre at the University of Bristol. The objective in developing the design of the AOT-100 has been to retain as many of the established principles as possible while making the instrument a readily usable tool that can be easily operated by non-specialists. The design has also made the instrument as compact as is achievable given the size of the constituent components and the optical path lengths required. Particles are trapped within a measurement cell accessible through...

Potential Applications The instrument enables the simultaneous and time resolved measurement of a very wide variety of parameters on single particles and so has potential applications in many fields of aerosol science. Examples of the measurements that can be made include: Particle size to a resolution of 1nm Changes in particle size with a time resolution of <1s Particle composition by Raman spectroscopy Particle refractive index Particle morphology Particle/vapour chemical reactions Particle/particle chemical reactions Some aspects of particle biochemistry Droplet viscosity Particle...