A modular microfluidic system comprising: a) a motherboard having a top surface with a plurality of interconnecting channels and a plurality of depressions formed therein, the motherboard further having integrated electrodes or holes for electrodes (1104a, 1104b, 1204a, 1204b, 1306a, 1306b, 1306c) to pass, the motherboard further having holes for optical fibers to pass; b) at least two channel inserts, wherein each channel insert is plugged into one of the interconnecting channels within said motherboard and comprises at least two openings and a fluid channel enabling a fluid flow between the two openings; c) at least two fitting components each having a tube with a first end (132a, 132b) and a second end (138a, 138b) d1) at least one micromodule, where the at least one micromodule is coupled via said fitting components to said channel inserts each micromodule having at least two openings and a channel formed therein allowing a fluid flow therethrough, d2) the openings of the micromodule coupled to the second end (138a, 138b) of a respective fitting component, the first ends (132a, 132b) thereof or said micromodule having an integral fitting component coupled to the openings (124a, 124b) of the channel inserts (102, 102") such that there is fluid communication through the micromodule, said fitting components, and said channel inserts; and e1) at least one of a separate pump-valve actuator or a heater having an electrical contact (111a, 111b) or an electrical contact unit which is sized to be positioned in at least one of the depressions formed within the motherboard, e2) the at least one of the pump-valve actuator, the heater, or the electrical contact unit is configured to be positioned between the motherboard and said at least one micromodule; and f) the heater adapted to supply heat to the micromodule, the electrical contact unit adapted to supply electricity to the micromodule (106") or to measure electrical signals from the micromodule (106"), and the pump-valve actuactor adapted to control fluid flow within the micromodule (106"") g) wherein each of the at least one micromodule, at least one of a separate pump-valve actuator or heater, and the at least two channel inserts are connected to each other and attached to the motherboard. a) a motherboard having a top surface with a plurality of interconnecting channels and a plurality of depressions formed therein, the motherboard further having integrated electrodes or holes for electrodes (1104a, 1104b, 1204a, 1204b, 1306a, 1306b, 1306c) to pass, the motherboard further having holes for optical fibers to pass; b) at least two channel inserts, wherein each channel insert is plugged into one of the interconnecting channels within said motherboard and comprises at least two openings and a fluid channel enabling a fluid flow between the two openings; c) at least two fitting components each having a tube with a first end (132a, 132b) and a second end (138a, 138b) d1) at least one micromodule, where the at least one micromodule is coupled via said fitting components to said channel inserts each micromodule having at least two openings and a channel formed therein allowing a fluid flow therethrough, d2) the openings of the micromodule coupled to the second end (138a, 138b) of a respective fitting component, the first ends (132a, 132b) thereof or said micromodule having an integral fitting component coupled to the openings (124a, 124b) of the channel inserts (102, 102") such that there is fluid communication through the micromodule, said fitting components, and said channel inserts; and e1) at least one of a separate pump-valve actuator or a heater having an electrical contact (111a, 111b) or an electrical contact unit which is sized to be positioned in at least one of the depressions formed within the motherboard, e2) the at least one of the pump-valve actuator, the heater, or the electrical contact unit is configured to be positioned between the motherboard and said at least one micromodule; and f) the heater adapted to supply heat to the micromodule, the electrical contact unit adapted to supply electricity to the micromodule (106") or to measure electrical signals from the micromodule (106"), and the pump-valve actuactor adapted to control fluid flow within the micromodule (106"") g) wherein each of the at least one micromodule, at least one of a separate pump-valve actuator or heater, and the at least two channel inserts are connected to each other and attached to the motherboard.