An injection device, comprising: a carrier (202, 3302, 4202, 5302), a needle (306, 308); a driver (320, 1398, 3320) coupled to the needle (306, 308), the driver (320, 1398, 3320) being slidable relative to the carrier between one first or two first and second retracted configurations, and a deployed configuration; a shuttle (340, 2420, 3340) configured to move the driver (320, 1398, 3320) between the first or the first and second retracted configurations, and the deployed configuration; an elastic biasing or resilient member coupled to the shuttle (340, 2420, 3340); characterised in that, it comprises a stop configured to move from a first configuration to a second configuration, wherein the stop is configured to impede longitudinal movement of the shuttle to maintain the driver (320, 1398, 3320) in the deployed configuration, and movement of the stop from the first configuration to the second configuration allows the shuttle (340, 2420, 3340) to move the driver (320, 1398, 3320) from the deployed configuration to the first or the second retracted configuration by an elastic deformation of the elastic biasing or resilient member; and one or two drive gears coupled to the carrier and to the driver (320, 1398, 3320); the shuttle (340, 2420, 3340) includes one or two rack gears configured to engage the one or two drive gears, wherein direct engagement of the one or two rack gears and the one or two drive gears moves the driver (320, 1398, 3320) from the first or the second retracted configurations, to the deployed configuration and direct engagement of the one or two rack gears and the one or two drive gears also moves the driver (320, 1398, 3320) from the deployed configuration to the first or second retracted configuration. a carrier (202, 3302, 4202, 5302), a needle (306, 308); a driver (320, 1398, 3320) coupled to the needle (306, 308), the driver (320, 1398, 3320) being slidable relative to the carrier between one first or two first and second retracted configurations, and a deployed configuration; a shuttle (340, 2420, 3340) configured to move the driver (320, 1398, 3320) between the first or the first and second retracted configurations, and the deployed configuration; an elastic biasing or resilient member coupled to the shuttle (340, 2420, 3340); characterised in that, it comprises a stop configured to move from a first configuration to a second configuration, wherein the stop is configured to impede longitudinal movement of the shuttle to maintain the driver (320, 1398, 3320) in the deployed configuration, and movement of the stop from the first configuration to the second configuration allows the shuttle (340, 2420, 3340) to move the driver (320, 1398, 3320) from the deployed configuration to the first or the second retracted configuration by an elastic deformation of the elastic biasing or resilient member; and one or two drive gears coupled to the carrier and to the driver (320, 1398, 3320); the shuttle (340, 2420, 3340) includes one or two rack gears configured to engage the one or two drive gears, wherein direct engagement of the one or two rack gears and the one or two drive gears moves the driver (320, 1398, 3320) from the first or the second retracted configurations, to the deployed configuration and direct engagement of the one or two rack gears and the one or two drive gears also moves the driver (320, 1398, 3320) from the deployed configuration to the first or second retracted configuration.