A methodology for forming a compressive strain layer with increased thickness that exhibits improved device performance and the resulting device are disclosed. Each test element is defined by a single test column that includes a quantity of a test material, such as gel material or a bead matrix, including a cover strip used to access the contents of the test column. At least one first channel is defined in the top surface. The mobile device operates as a user interface. At least one of the controls is operable to variably select a display format for the at least one display region.