Here we present an advanced microfluidics microchip technology developed for systematic high-throughput screening of protein interactions and efficient construction of recombinant antibody libraries.A novel chemistry enables custom synthesis of peptides or oligonucleotides directly on the high density microfluidic chip at addressable chip locations.The chip microfluidics provide a controlled, enclosed environment to conduct 4K-30K simultaneous protein binding reactions on a single chip.We will present various application examples including use of this microfluidic array technology to screen thousands of epitope sequences and to generate millions of protein coding oligos for construction of antibody libraries.Our ultimate goal is to provide new, powerful research and clinical study tools to address the critical needs in proteomic research, clinical diagnosis, and therapeutic treatment.