design research

hi all,
I have asked this question many a times but have still not found an answer to it except one guy showing me way to CfDR…please dispel the darkness this time

:" I want to study design research on a formal basis, in that, I want to study and do projects that lemme expore the various methodologies using which one can approch a given design challenge.Is there an institutuion that focuses on design research of such kind.I have an MDes in Product Design from the best school in India known as IIT Delhi (Indian forr IILinois) and am working for a US based pd firm that is world leader in water solutions."

Please lemme know if PhD/MDes/MS would suit my needs.I want to cater to Usability , human factors aspect of Design as my research focus.