FIG 9c - a robotic hand being controlled using the open circuit voltages of FIG. 9b; FIG. 10, comprising FIGs. 10a t o lOe, illustrates: FIG. 9b - open circuit output voltages from the sensors, for each gesture shown in FIG 9a; and FIG. 9a - images of hand gestures performed with four sensors, one mounted t o each finger; FIG. 9, comprising FIGS. 9a t o 9c, illustrates: FIGs. 8c t o 8f - the voltage outputs of the four arches of the two, two-arch sensors of FIG. 8a for American Sign Language letters A, B, C and D respectively; FIG. 8a - image of two, two-arch sensors mounted t o a human hand; FIG. 8b - illustrated hand forming letters A, B, C and D in American Sign Language; and FIGs. 7h and 7 1 - voltage outputs at both the first and second of the two sensors of the device of FIG. 7e, and both the first and second of the two arches of the device of FIG. 7i, respectively, at various angles of bending of the first and/or second finger joints; FIG. 8, comprising FIGs. 8a t o 8f, illustrates: FIGs. 7g and 7k - voltage outputs at a second of the two sensors of the device of FIG. 7e, and a second of the two arches of the device of FIG. 7i, respectively, at various angles of bending of a second finger joint; and FIGs. 7f and 7j - voltage outputs at a first of the two sensors of the device of FIG. 7e, and a first of the two arches of the device of FIG. 7i, respectively, at various angles of bending of a first finger joint; FIG. 7i - design incorporating a two-arch sensor, each arch being located at a respective finger joint; FIG. 7e - design incorporating two separate sensors located at respective finger joints (e.g. knuckles); FIG. 7d - image of the sensor and hand of FIG. 7a, with the hand bent t o activate both the first and second arches of the two-arch sensor; FIG. 7c - image of the sensor and hand of FIG. 7a, with the hand bent t o activate a second of the arches of the two-arch sensor; FIG. 7b - image of the sensor and hand of FIG. 7a, with the hand bent t o activate a first of the arches of the two-arch sensor; FIG. 7a - image of a two-arch sensor for measuring finger movements, mounted t o a hand;