A bioprinter for controlled in-situ formation and deposition of biopolymeric sheets and planar tissues on surfaces, comprising: a) support frame and a printhead attached to said support frame, said printhead including a first array of extrusion channels and at least a second array of extrusion channels located with respect to said first array such that in operation said first array is proximally adjacent to said surface, an end section of said printhead having a width W such that said first and second arrays span said width W; b) a first reservoir attached to said frame, said first array of extrusion channels being in flow communication with said first reservoir of biopolymer to be extruded onto the surface, a second reservoir of liquid attached to said frame, said second array being in flow communication with said second reservoir of liquid to be extruded along with the extruded biopolymer, and including a first dispensing mechanism associated with said first reservoir being configured to dispense biopolymer at a flow rate of QM, and a second dispensing mechanism associated with said second reservoir being configured to dispense the liquid at a flow rate of QC; c) a drive mechanism attached to said frame such that when activated by the operator, said printhead is driven along the surface located a vertical height H above the surface at a preselected velocity V; d) a controller connected to said drive mechanism and said first dispensing mechanism and programmed such upon activating said drive mechanism, said first dispensing mechanism dispenses biopolymer at the flow rate QM a layer of thickness t, which satisfies the condition QM = W·V·H(6(t/H) - 6( t/H) 2 +3( t/H) 2 (μ C /μ M)) / (6( t/H) (μ C /μ M)- 6( t/H) +6), wherein μM is the viscosity of the biopolymer and μC is the viscosity of the liquid to be extruded along with the biopolymer. a) support frame and a printhead attached to said support frame, said printhead including a first array of extrusion channels and at least a second array of extrusion channels located with respect to said first array such that in operation said first array is proximally adjacent to said surface, an end section of said printhead having a width W such that said first and second arrays span said width W; b) a first reservoir attached to said frame, said first array of extrusion channels being in flow communication with said first reservoir of biopolymer to be extruded onto the surface, a second reservoir of liquid attached to said frame, said second array being in flow communication with said second reservoir of liquid to be extruded along with the extruded biopolymer, and including a first dispensing mechanism associated with said first reservoir being configured to dispense biopolymer at a flow rate of QM, and a second dispensing mechanism associated with said second reservoir being configured to dispense the liquid at a flow rate of QC; c) a drive mechanism attached to said frame such that when activated by the operator, said printhead is driven along the surface located a vertical height H above the surface at a preselected velocity V; d) a controller connected to said drive mechanism and said first dispensing mechanism and programmed such upon activating said drive mechanism, said first dispensing mechanism dispenses biopolymer at the flow rate QM a layer of thickness t, which satisfies the condition QM = W·V·H(6(t/H) - 6( t/H) 2 +3( t/H) 2 (μ C /μ M)) / (6( t/H) (μ C /μ M)- 6( t/H) +6), wherein μM is the viscosity of the biopolymer and μC is the viscosity of the liquid to be extruded along with the biopolymer.