An apparatus and a method for use with a device for delivery of a therapeutic fluid into a body of a patient andor for sensing of a bodily analyte are disclosed. The film forming composition and resulting coating properties can be tailored to suit the specific exposure wavelength and device fabrication and design requirements. The angular position is a measure of the stickness of the particulate solid. A flexible display is configured to move between one state where a majority of the flexible display is positioned inside the housing and rolled around the core and another state where a majority of the flexible display is moved out of the housing through the opening and positioned outside of the housing to form a viewing surface.