A curvilinear plate for a heat exchanger is provided. The curvilinear plate can include an inner plate defining a plurality of first grooves and an outer plate defining a plurality of second grooves. The outer plate is attached to the inner plate with the plurality of first grooves and the plurality of second grooves substantially aligned to define a plurality of channels therebetween. Each channel extends from a first opening on a first portion of a first end of the curvilinear plate to a second opening on a second portion of the first end. A method is also generally provided for forming a curvilinear plate.