A system for additive manufacturing of three-dimensional structures, the system comprising: - at least one print head for receiving and dispensing materials, the materials comprising at least one first material, the first material comprising a sheath fluid, and at least one second material, the second material comprising a hydrogel, the print head comprising: - an orifice for dispensing the materials; - microfluidic channels comprising one or more first channels for receiving and directing the first material and one or more respective second channels for receiving and directing the second material, the second channels intersecting at a first intersection point with the first channels, the second and first channels joining together at the first intersection point to form a dispensing channel which extends to the orifice ; and - fluidic switches , each fluidic switch corresponding to one of the microfluidic channels in the print head and configured to allow or disallow fluid flow in the microfluidic channels of the print head when actuated; - a receiving surface for receiving a first layer of the materials dispensed from the orifice; - a positioning unit for positioning the orifice of the print head in three-dimensional space, the positioning unit operably coupled to the print head ; and - a dispensing means for dispensing the materials from the orifice of the print head . - at least one print head for receiving and dispensing materials, the materials comprising at least one first material, the first material comprising a sheath fluid, and at least one second material, the second material comprising a hydrogel, the print head comprising: - an orifice for dispensing the materials; - microfluidic channels comprising one or more first channels for receiving and directing the first material and one or more respective second channels for receiving and directing the second material, the second channels intersecting at a first intersection point with the first channels, the second and first channels joining together at the first intersection point to form a dispensing channel which extends to the orifice ; and - fluidic switches , each fluidic switch corresponding to one of the microfluidic channels in the print head and configured to allow or disallow fluid flow in the microfluidic channels of the print head when actuated; - an orifice for dispensing the materials; - microfluidic channels comprising one or more first channels for receiving and directing the first material and one or more respective second channels for receiving and directing the second material, the second channels intersecting at a first intersection point with the first channels, the second and first channels joining together at the first intersection point to form a dispensing channel which extends to the orifice ; and - fluidic switches , each fluidic switch corresponding to one of the microfluidic channels in the print head and configured to allow or disallow fluid flow in the microfluidic channels of the print head when actuated; - a receiving surface for receiving a first layer of the materials dispensed from the orifice; - a positioning unit for positioning the orifice of the print head in three-dimensional space, the positioning unit operably coupled to the print head ; and - a dispensing means for dispensing the materials from the orifice of the print head . <EOS>