This technology describes a method for performing immediate in-line sample heating to promote the required chemical reactions for amplification, activation, or detection, depending on the thermodynamics of the particular assay involved. The basis of this technology is a method that employ microwave energy absorption to instantaneously heat fluidic partitions without heating the device itself or any oil, or entrapped air. With this invention little energy is wasted heating the device and instead is absorbed heating the aqueous solution within the microfluidic device’s chambers, channels, or reservoirs. This will allow the most efficient, fastest, and best method for energizing chemical reactions in microfluidics devices. Additionally, this system allows for optical addressability of the cavity or waveguide, which allows fluorescence detection of temperature, pH, nucleic acid amplification for PCR, or direct optical observation of cell lysis, sedimentation, and other signals and observations under test for the real-time microfluidic device.