Fig. 1. A programmable temperature regulation system with an attached microfluidic chip. (A) Cross-section of the temperature regulation system placed under a microscope with a mounted microfluidic chip. The inset depicts immobilized single microalgae in microwell geometries within the microfluidic chip. (B) A photograph of the heat-stage with an attached PDMS/glass microfluidic chip. (C) Attachment of the microfluidic chip on the heat-stage. The upper inset displays a single cell array and the lower inset the design of the heater and temperature sensor arrays in the actively heated area, here referred to as the temperature control window. (D) Schematic of the different parts of the temperature regulation system. Using the temperature controller, the power applied to each heater is individually regulated via a feedback loop, which reads the temperature of the neighboring temperature sensor.