A test strip for sampling a bodily fluid may include multiple layers of a substrate material, an adhesive between at least some of the multiple layers, and a microfluidic channel formed between at least some of the multiple layers. The test strip may further include multiple electrodes on one of the multiple layers, positioned and partially exposed within the microfluidic channel, an additional material positioned at or near an entrance to the microfluidic channel, to selectively limit the flow of at least one of bubbles or debris into the microfluidic channel, and at least one exit port in at least one of the multiple layers to allow for release of pressure from the test strip. In some embodiments, the test strip is a saliva analysis test strip. In some embodiments, the test strip includes multiple exit ports to prevent blockage of sample flow.