In our modern world, many biomedical tasks are increasingly being accomplished by “Lab-on-a-chip devices.” At the core of these devices is the ability to move, sort, and test samples of interest. Many microfluidic devices rely on fluid flows created by external pumps to move objects around the microenvironment. Fluidic actuation is generally safe for many types of samples and can be used in conjunction with other technologies such as fluorescence imaging. But for true 3D control of individual particles, rather than aggregates, we have to look to optical trapping. Optical traps use electromotive forces created by focused laser beams to trap tiny dielectric particles; this allows for precise control of the position of a particle.
Now in a paper by Erben et al. a new hybrid technique has been proposed. The team uses thermoviscous flows to move and trap individual particles. Notably, the technique is insensitive to particle composition and does not require the particle to be illuminated directly with light, thereby reducing unwanted photochemical interactions. Though the research is in its early days, the technique could be useful for passive positioning of particles that otherwise could not be manipulated, or as a way of developing dynamically reconfigurable microfluidic flows.
You must log in
to add comments.