Zero ischemia laparoscopic radio frequency ablation assisted tumor enucleation has been proved to enable tumor excision with relatively better renal function preservation comparing with conventional laparoscopic partial nephrectomy for T1a renal cell carcinoma (RCC) in a randomized clinical trial in single center. The investigators want to explore this technique to robotic surgery and add suture-less technique to T1 RCC patients in randomized clinical trial.