Institute of Physics lectures in Salisbury; Making small machines, from millimetres to molecules – Dr Jack Cohen

Illustrations of self-assembled colloidal structures. (a) Highly ordered regions with hexagonal symmetry extending over assembled from functionalized (patchy) colloidal silica particles. The colloidal structure exhibits a photonic band gap in the visible light range. (b) Regions showing co-existing hexagonal and square symmetry, from [13]. (c, d) Confocal microscope images illustrating highly-ordered self-assembled structures in 'ionic' colloidal crystals of oppositely charged particles assembled from positive (red, ) and negative (green, ) polymethylmethacrylate spheres. (e, f) Electric field induced structures in the same system: stationary bands perpendicular to the field directions (e) and lanes of oppositely moving particles parallel to the field direction, emerging for larger amplitudes of the applied electric field (f).

Illustrations of self-assembled colloidal structures. (a) Highly ordered regions with hexagonal symmetry extending over assembled from functionalized (patchy) colloidal silica particles. The colloidal structure exhibits a photonic band gap in the visible light range. (b) Regions showing co-existing hexagonal and square symmetry, from [13]. (c, d) Confocal microscope images illustrating highly-ordered self-assembled structures in ‘ionic’ colloidal crystals of oppositely charged particles assembled from positive (red, ) and negative (green, ) polymethylmethacrylate spheres. (e, f) Electric field induced structures in the same system: stationary bands perpendicular to the field directions (e) and lanes of oppositely moving particles parallel to the field direction, emerging for larger amplitudes of the applied electric field (f). Igor S Aranson. Active colloids. Physics-Uspekhi, Volume 56, Number 1 © 2013 Uspekhi Fizicheskikh Nauk and P N Lebedev Physics Institute of the Russian Academy of Sciences

Poster for Dr Jack Cohen

Poster for Dr Jack Cohen

The South West Branch of the Institute of Physics regularly have events in Salisbury. The next one will be in November (18th) with Dr Jack Cohen of the University of Warwick talking about his research on very, very small machines.

In this talk I will give a broad consideration of methods and examples of making parts and machines from millimetres down to molecules in size. I will mention some traditional methods, but I will mostly concentrate on approaches from soft matter physics with some examples provided from biophysics. This will include self-propelled micron scale particles known as Active Colloids, a topic from my research, as published in Phys. Rev. Lett. 112, 068302 (2014).

More details on their events can be found on the IoP SW Branch website and their events are also syndicated through to the calendar on this website under the IoP category.