Figure 1.

(a) Test setup and design of the optical space-time coded microfluidic device. The samples enter the microfluidic channel from the inlet by a syringe pump. The laser beam illuminates the microfluidic channel through the mask with a pattern in (b). FS and LAS represent forward scattering and large angle scattering signals detected by 2 Si PIN photoreceivers with a 3 × 3 mm² photosensitive area. (b) The detailed design of the spatial mask. Four transparent trapezoidal slits are formed on the mask to encode the waveforms of particles depending on their travel positions. Below the mask pattern is the schematic of an ideal waveform showing 4 peaks with pulse width P1 to P4 corresponding to the bead’s position along the x-direction.