A flow path sealing structure according to at least one embodiment of the present disclosure, which is disposed on a way of a flow path formed by fusion bonding a pair of resin sheets that are superimposed on each other, includes a widened portion surrounded by a widened seal portion formed by fusion bonding together the pair of resin sheets around a periphery thereof, and one end and another end of which are in communication with the flow path, together with being formed to be wider than the flow path, and a weakly sealed portion formed to extend in a widthwise direction in the widened portion, and which partitions the widened portion in a liquid-tight and airtight manner into the one end and the other end, together with being capable of being opened by increasing an internal pressure of the widened portion.

A process of constructing an air tight and water tight seam, comprising cutting a sheet of selected material into two or more panels, sealing the panels at respective selected edges using an ultrasonic machine to form a seam, overlaying the seam with a tape made of the same selected material, and sealing the tape and seam using a radio frequency (RF) welding machine.

A fluidic device including an inorganic solid support attached to an organic solid support by a bonding layer, wherein the inorganic solid support has a rigid structure and wherein the bonding layer includes a material that absorbs radiation at a wavelength that is transmitted by the inorganic solid support or the organic solid support; and a channel formed by the inorganic solid support and the organic solid support, wherein the bonding layer that attaches the inorganic solid support to the organic solid support provides a seal against liquid flow. Methods for making fluidic devices, such as this, are also provided.