A portable device for removal of metabolic waste from the blood of patient having kidney disease or in need of hemodialysis is provided. Methods of hemodialysis employing the portable device beneficially obtain a dialysate by electrokinetic means from excess fluid in the peripheral blood of the patient in need thereof. The methods employ a branched microfluidic channel for the use of ion concentration polarization to separate charged from neutral species in blood to obtain the dialysate for undergoing hemodialysis. Beneficially the methods and device are resistant to biofouling, remove the need for a dialysate and/or dialysate reservoir, and provide a disposable, wearable device.