Patent ID: 7060419

Claim:
A process for producing microfluidic articles comprising the steps of (a) preparing a photoreactive composition comprising (1) at least one reactive species that is a polymer or a polymer precursor and that is capable of undergoing an acid- or radical-initiated chemical reaction and (2) at least one multiphoton photoinitiator system comprising photochemically effective amounts of (i) at least one multiphoton photosensitizer that is capable of simultaneously absorbing at least two photons, (ii) optionally, at least one electron donor compound different from the multiphoton photosensitizer and capable of donating an electron to an electronic excited state of the photosensitizer, and (iii) at least one electron acceptor compound that is capable of being photosensitized by accepting an electron from an electronic excited state of the photosensitizer, resulting in the formation of at least one free radical and/or acid; (b) exposing a portion of said composition to light sufficient to cause simultaneous absorption of at least two photons, thereby forming exposed and unexposed portions of said composition, and thereby inducing at least one acid- or radical-initiated chemical reaction in said exposed portion; and (c) removing either said exposed or said unexposed portion of said composition, so as to form a microfluidic article comprising a seamless polymer matrix that defines at least one inlet, at least one outlet, and a microfluid processing architecture that is capable of fluidic communication with said inlet and said outlet and that is otherwise fully enclosed within said polymer matrix.