Abstract
The DNA chip is required of high sensitivity and low cost for practical medical service. We have used polymethylmethacrylate (PMMA) as a substrate of DNA chip for low cost. However, PMMA cannot adhere DNA due to its hydrophobicity. In this work, in order to change the PMMA to be hydrophilic, various ions were irradiated on the surface of PMMA by using an Electron Cyclotron Resonance (ECR) ion shower apparatus. The contact angle of water on the surface of PMMA was reduced by 90%, 84% and 85% by irradiating Ar^+, O_x^+ and N_x^+ ion at best suited condition, respectively.
