A process for manufacturing a microfluidic device including: 1. providing two substrates which, when assembled, define a microfluidic structure; 2. coating at least one of the surfaces defining the microfluidic structure with a coating composition including: a. a monomer A including one moiety represented by CH.sub.2CR.sub.1R.sub.2 wherein R.sub.1 represents H or CH.sub.3 and R.sub.2 represents COO or CONH, and a non-ionic hydrophilic moiety; b. a monomer B including two or more moieties represented by CH.sub.2CR.sub.1R.sub.2 wherein R.sub.1 represents H or CH.sub.3 and R.sub.2 represents COO or CONH, and a non-ionic hydrophilic moiety; 3. assembling the substrates to obtain a microfluidic structure between the first and the second substrate; and 4. at least partially irradiating the assembly with light to crosslink the liquid coating to bond the substrates and to obtain a crosslinked coating inside the microfluidic structure.