Single cell trapping and stretching in an optofluidic chip fabricated by femtosecond laser micromachining

The investigation of the mechanical properties of individual cells is of great interest for the comprehension of basic biological mechanisms and for the early detection of several diseases. Optical stretchers based on fibers have widely demonstrated their effectiveness for this kind of analysis. Nevertheless, in order to turn such a device into an operative tool for biological studies, it is essential to achieve the integration on the same chip of both microfluidic and optical components. Here we present an integrated optical stretcher (IOS) able to perform mechanical analysis of single cells without physical contact and with high reproducibility. The chip is fabricated in a fused silica glass substrate by exploiting femtosecond laser micromachining, a technique that allows fabricating both the optical waveguides and the microchannel with great accuracy and 3D capability.