The 28th Ockham Lecture - 'How to Trap Your Nano-Object'

Given by Professor Madhavi Krishnan, Fellow and Tutor in Chemistry at Merton College, and Associate Professor of Physical Chemistry at the University of Oxford.

The lecture was followed by a Q&A session.

Abstract

"A microscopic bit of matter in solution is in continuous motion. Pummelled at random by the solvent, it engages in a Brownian walk that will eventually take it far away from where we first started to observe it. At the nanometre scale, even gravity or other external fields are often too weak to influence the trajectory of the object. Relying on like-charge electrostatic repulsion, we recently achieved the ability to stably spatially confine a single charged molecule in a room temperature solution, without recourse to external fields. Exploiting equilibrium thermodynamics to realise this goal, our approach presents a paradigm shift in the context of a century-old effort to trap matter using applied fields. This experimental advance has not only opened up avenues in ultrasensitive biomolecular measurement and detection, but is also furnishing deeper basic insight into the electrostatic interaction in solution, and may pave the way to understanding the enigmatic experimental observation that like charged objects can attract one another."

The Ockham Lecture series

The Merton College Physics Lecture (the Ockham, or Occam, Lecture, so named in honour of one of the greatest—if unattested—alumni of the College and of his philosophical principle of intellectual discipline) started in 2009 and is held once a term. It is organised by the physics tutors of the College to promote both intellectual curiosity and social cohesion of the Merton Physics community.

Attendance is by invitation: All Merton physicists (and sympathisers!) belonging to the three Common Rooms (JCR, MCR and SCR) are invited, as are the Old Members. Their guests are also accommodated, space permitting.