Abstract: An actuator for a joint comprises a bladder-shaped chamber 5 whose one end is secured to an arm 2 by a mounting 6, whilst a bundle of fibres 7 extend from the other end of the chamber member 5 to a junction 8 on another arm 3. The rear wall 9 of the chamber member 5 is formed from woven bi-directional fibres 10 whilst the outer wall is defined by an array of high tensile fibres 11, at least some of which extend from the fibre bundle 7. The fibres 7, 10 and 11 are embedded in elastic material. When a pneumatic or hydraulic fluid is pumped through an inlet 12 to the chamber member 5, the latter expands and the fibres 11 bow outwardly, thus pulling on the fibres 7 and raising the arm 3, with the respect to the arm 2, to lift a weight 13.

Abstract: High tensile electrically-conductive filaments 1 are connected to the two ends of an electrically-conductive elastic block 2 and the whole is embedded within an elastic covering 3. As the sensor is put under tension the elastic block stretches and the resistance of the sensor, as measured between the two sets of filaments 1, increases proportionally to the degree of extension.