Profile

I have studied in Italy and France and I am now a researcher at Imperial College London, where I work in collaboration with Durham University and the Central Laser Facility in Harwell, Oxford.

In my research, I use lasers to trap, move and deform very small objects, such as glass/plastic beads or liquid drops.

 
Objects trapped by light
Laser is an amazing tool for scientists as it allows us to do many things. For instance,  if we point a laser against a tiny little particle, we can trap that particle and move it around as we like. For that to happen, the particle has to be very small, something like 20 times smaller than a human hair. Such a laser technique is called “optical tweezers”. To see “Optical Tweezers” in action, check this video where glass beads are handled within a water environment to reproduce a living version of the famous Tetris game.

 
Objects deformed by light
In my current research project, I work with optical tweezers to study the behaviour of oil droplets in water. Oil drops are like rigid spheres, which keep their spherical shape even when trapped by laser. By adding some chemicals, oil drops can turn very soft so that we can use a laser to deform them and change their shape.

This picture shows how laser traps can be used to deform a spherical oil drop into an ellipse, a triangular and a square-shaped drop . If we add some other chemicals into the drop and we expose it to another light source (called UV light), we can turn the soft liquid drop into a solid rigid particle. Such a technique allows us to produce very small solid particles with very complex shapes. Those complex shape particles are very precious in science and industry. Indeed, even though they are very difficult to make, they have several applications in biotechnology, nanotechnology, electronics, material science, cosmetic industry and many more!

Droplet network created by light
Optical traps can also be used to deform soft drops to the point they break up into two drops. However, the resulting two drops are not completely separated but they are still connected via tiny “invisible” threads. We can therefore use optical traps to split one drops in many more and thus create a network of drops and threads. Laser can also be used to pump liquid from one drop to the other.
This figure shows how three small drops are generated by pinching off the end of one single drop (Step 1 and 2) and how the liquid from the central drop is pumped into the lateral drops (Step 3 and 4). The threads connecting the central drop to the lateral ones are so small that cannot be seen. An exciting application for those drop networks is to use them as miniaturized chemical laboratories. For instance, we can pump liquid A from one drop and liquid B from another drop and let a chemical reaction A+B happen within a third drop.

Remember, all those operations are done without actually touching any drops at all but just using light, isn’t it amazing?

The only typical thing during my working days is a cup of coffee – one in the morning and one in the afternoon. Apart from that, every day is usually different from the previous one and the one next.

Sometimes I can spend the whole day in the lab, either performing experiments or building/improving the tools I need to run my experiments. Some other days,  I am in my office in front of my computer, analysing experimental data, carrying out computer simulations, writing reports/presentations/papers or reading scientific literature to keep myself up-to-date about the latest in my research field. I have also meetings with my colleagues to discuss the development of our research and I attend lectures and training courses to  extend my knowledge and develop new skills.