HeatChips: A versatile, low-cost and microscopy-compatible heating system for microfluidic devices

Abstract

Microfluidic systems are widely used in biology for their ability to control environmental parameters. Specifically, cell culture or chemistry in microfluidic devices requires tight control of the temperature. In addition, microfluidic devices can be made transparent to visible light and compatible with inverted microscopes. Yet, the current temperature control systems that allow high-resolution microscopy either require a set of complex secondary channels, a bulky, expensive, and microscope-dependent incubator, or fail to produce a homogenous temperature profile across the sample area. Here, we present HeatChips, a simple, cost-effective system to heat samples inside PDMS-based microfluidic devices in a homogeneous manner. It is based on a transparent heating glass in contact with the top of the microfluidic device, and a contactless, infrared temperature sensor attached to the objective that directly reads the temperature of the bottom of the chip. This portable system is compatible with most chip designs and allows imaging of the sample on inverted microscopes for extended periods of time without any optical restriction, for a cost of less than 100{euro}. Specifications table [Table 1]