A microchannel heat exchanger was designed for diesel waste heat recovery and its performance was evaluated. The 21x15x8 cm unit was constructed from diffusion brazed stainless steel lamina and weighed 11 kg. Operating from a 13.4 kW generator with an exhaust temperature of 500 °C the unit delivered 11.1 kW of thermal energy at the design point with an effectiveness of 0.87. If coupled with an organic Rankine bottoming cycle this has the potential of boosting system power output by 35%. Performance was found to be insensitive to cold side flow conditions. Soot accumulation was found to be problematic, which caused a steady exhaust pressure rise at the device but did not affect the thermal performance. / Graduation date: 2012