Abstract: An actuator comprises: a cavity containing a working medium (B) that reversibly expands as it undergoes a phase change from a solid to a liquid state; a diaphragm disposed adjacent the cavity such that expansion and contraction of the expandable working medium (B) causes the diaphragm to deflect, and a semiconductor element (A) disposed in the cavity. The semiconductor element (A) is operable in a first mode to heat the working medium (B) to cause it to undergo the phase change into the liquid state, and is operable in a second mode to measure the temperature at the semiconductor element (A). The corresponding actuation method is also disclosed.

Abstract: A one-way valve (1) comprises a seat (5) and a membrane (4) having an inner portion (4a) that is stretched over the seat, wherein, in use, the inner membrane portion is selectively deflected from the seat such that a fluid path is created from one side of the membrane to the other so as to open the valve, and wherein an outer peripheral portion (4b) of the membrane is stiffer than the inner portion such that the membrane deflection is substantially restricted to only the inner portion. The one-way valve may be used in a pump for an infusion system.

Abstract: An actuator comprises a cavity containing a working medium that reversibly expands as it undergoes a phase change from a solid to a liquid state, a diaphragm disposed adjacent the cavity such that expansion and contraction of the expandable working medium causes the diaphragm to deflect, and a semiconductor element disposed in the cavity, wherein the semiconductor element is adapted to heat the working medium to cause it to undergo the phase change into the liquid state. The actuator may be used in a pump for an infusion system.

Abstract: A one-way valve comprises a seat and a membrane having an inner portion that is stretched over the seat, wherein, in use, the inner membrane portion is selectively deflected from the seat such that a fluid path is created from one side of the membrane to the other so as to open the valve, and wherein an outer peripheral portion of the membrane is stiffer than the inner portion such that the membrane deflection is substantially restricted to only the inner portion. The one-way valve may be used in a pump for an infusion system.