In earlier works [1,2], we proved that fiber arrays are the basis of an open digital microfluidics. Droplets can be manipulated on fibers and various processes such as droplet motion, fragmentation, trapping, release, mixing and encapsulation were studied on fiber arrays.
In our last paper , we use optical fibers in order to probe the content of droplets placed at fiber crossings. Fluorescence excited in five droplets by a blue light is shown on the top-left picture. The associated peak of emitted light is also shown for each droplet. The main benefits of this fiber-based detection system are the absence of fibers functionalization, the use of microliter volumes of target and probe species, their separation before interaction and a better detection limit compared to cuvettes setups. This opens ways to develop biosensors within fiber arrays.
 T.Gilet, D.Terwagne, N.Vandewalle, Digital microfluidics on a wire, Appl. Phys. Lett. 95, 014106 (2009)
 T.Gilet, D.Terwagne, N.Vandewalle, Droplets sliding on fibres, Eur. Phys. J. E 31, 253-262 (2010)
 M.Lismont, N.Vandewalle, B.Joris, L.Dreesen, Fibers based optofluidic biosensor, Appl. Phys. Lett. 105, 133701 (2014) – PDF