A device for detecting a viscosity property of a fluid, comprising: a body region: a first flexible member having a first end and a second end, said first end being fixedly located on said body region; a second, reference flexible member having a first end and a second end, said first end being fixedly located on said body region; each flexible member (125a, 125b) comprising an integrated heater element (103a, 103b) arranged to heat the respective flexible member (125a, 125b) to induce bending of said flexible member (125a, 125b); means for providing an electrical pulse to the integrated heater elements (103a, 103b) to induce said bending; and each flexible member (125a, 125b) further comprising at least a first layer having a first coefficient of thermal expansion and a second layer having a second, different coefficient of thermal expansion, and a respective sensor (105a, 105b) arranged to provide a signal indicative of the movement of the respective flexible member; wherein the sensor of the second, reference flexible member is configured to be less sensitive to longitudinal strain caused by bending of the respective flexible member than the sensor of the first flexible member, with at least one of the flexible members including at least one additional portion of material for substantially equalising the thermal conductivity distribution of said flexible members (125a, 125b); and wherein the device is configured to: determine a sensor signal of the first flexible member and a reference signal of the second flexible member, which are indicative of the deflection of the respective flexible member; and subtract the reference signal from the sensor signal to leave a signal having substantially only a strain component, which is indicative of the viscosity property of the fluid. a body region: a first flexible member having a first end and a second end, said first end being fixedly located on said body region; a second, reference flexible member having a first end and a second end, said first end being fixedly located on said body region; each flexible member (125a, 125b) comprising an integrated heater element (103a, 103b) arranged to heat the respective flexible member (125a, 125b) to induce bending of said flexible member (125a, 125b); means for providing an electrical pulse to the integrated heater elements (103a, 103b) to induce said bending; and each flexible member (125a, 125b) further comprising at least a first layer having a first coefficient of thermal expansion and a second layer having a second, different coefficient of thermal expansion, and a respective sensor (105a, 105b) arranged to provide a signal indicative of the movement of the respective flexible member; wherein the sensor of the second, reference flexible member is configured to be less sensitive to longitudinal strain caused by bending of the respective flexible member than the sensor of the first flexible member, with at least one of the flexible members including at least one additional portion of material for substantially equalising the thermal conductivity distribution of said flexible members (125a, 125b); and wherein the device is configured to: determine a sensor signal of the first flexible member and a reference signal of the second flexible member, which are indicative of the deflection of the respective flexible member; and subtract the reference signal from the sensor signal to leave a signal having substantially only a strain component, which is indicative of the viscosity property of the fluid. a first flexible member having a first end and a second end, said first end being fixedly located on said body region; a second, reference flexible member having a first end and a second end, said first end being fixedly located on said body region; each flexible member (125a, 125b) comprising an integrated heater element (103a, 103b) arranged to heat the respective flexible member (125a, 125b) to induce bending of said flexible member (125a, 125b); means for providing an electrical pulse to the integrated heater elements (103a, 103b) to induce said bending; and each flexible member (125a, 125b) further comprising at least a first layer having a first coefficient of thermal expansion and a second layer having a second, different coefficient of thermal expansion, and a respective sensor (105a, 105b) arranged to provide a signal indicative of the movement of the respective flexible member; wherein the sensor of the second, reference flexible member is configured to be less sensitive to longitudinal strain caused by bending of the respective flexible member than the sensor of the first flexible member, with at least one of the flexible members including at least one additional portion of material for substantially equalising the thermal conductivity distribution of said flexible members (125a, 125b); and wherein the device is configured to: determine a sensor signal of the first flexible member and a reference signal of the second flexible member, which are indicative of the deflection of the respective flexible member; and subtract the reference signal from the sensor signal to leave a signal having substantially only a strain component, which is indicative of the viscosity property of the fluid. determine a sensor signal of the first flexible member and a reference signal of the second flexible member, which are indicative of the deflection of the respective flexible member; and subtract the reference signal from the sensor signal to leave a signal having substantially only a strain component, which is indicative of the viscosity property of the fluid.