Techniques for ultra-high density connection are disclosed. In one embodiment, an ultra-high density connector includes a bundle of substantially parallel elongate cylindrical elements, where each cylindrical element is substantially in contact with at least one adjacent cylindrical element. Ends of the elongate cylindrical elements are disposed differentially with respect to each other to define a three-dimensional interdigitating mating surface. At least one of the elongate cylindrical elements has an electrically conductive contact positioned to tangentially engage a corresponding electrical contact of a mating connector.