A polymeric micro-optical interface for flow monitoring in biomicrofluidics

Abstract

We describe design and miniaturization of a polymeric optical interface for flow monitoring in biomicrofluidics applications based on polydimethylsiloxane technology, providing optical transparency and compatibility with biological tissues. Design and ray tracing simulation are presented as well as device realization and optical analysis of flow dynamics in microscopic blood vessels. Optics characterization of this polymeric microinterface in dynamic experimental conditions provides a proof of concept for the application of the device to two-phase flow monitoring in both in vitro experiments and in vivo microcirculation investigations. This technology supports the study of in vitro and in vivo microfluidic systems. It yields simultaneous optical measurements, allowing for continuous monitoring of flow. This development, integrating a well-known and widely used optical flow monitoring systems, provides a disposable interface between live mammalian tissues and microfluidic devices making them accessible to detection/processing technology, in support or replacing standard intravital microscopy.

Real-Time Detection of Slug Velocity in Microchannels

“…The boundary value is debatable, but, generally in microfluidics, it is assumed to be Re = 1. To enhance the process nonlinearity and be able to evaluate the robustness of the methodology proposed in our experiments, its value was in the range [1,13]. The Capillary number on the order 10 −3 , as it is in the experiments presented, assures the slugs' formation.…”

“…The challenge nowadays is to have methodologies based on low cost technologies easily embedded in a portable device for real-time applications. In this context, data-driven approaches based on monitoring optical signals [9] can represent a good alternative since they are non-invasive, offer an easy integration of optical sensors with the microfluidic chips [12,13], and, in future development, the possibility of being even embedded in a chip [14]. In the micro-optofluidic chip presented in [14], the advantage of the integration of micro-optical and microfluics components in one device is proved by taking the advantage of advanced signal analysis methodology to process the optical information and control the flow.…”

A polymeric micro-optical system for the spatial monitoring in two-phase microfluidics

“…In our previous studies, a PDMS micro-optical interface, based on off-chip detection, for flow monitoring both in vitro and in vivo (microcirculation) systems was introduced (Bucolo et al 2008;Sapuppo et al 2010). Our approach is based on time series extraction and analysis representing a powerful tool to provide automatic analysis in LOC for pointwise flow information.…”

Intravital microscopy in a dorsal skinfold chamber: hemodynamics, tumor angiogenesis and inflammation

“…Another recent study applied a polymeric micro-optical interface for flow monitoring in a hamster dorsal skinfold chamber model. 27 Although this concept of optical monitoring has a somewhat noisy signal, this development has shown a possible application in flow monitoring in an in vivo experiment.…”