A flexible device 100 which at least partially encloses an appendage of a user, the device having a support structure 101 with an inner (wearer contacting) side 102 and an outer side 106, and a section of flexible circuitry 103 towards the inner side. The device is preferably a wrist device that wraps around and can be worn on a users wrist. The device may include wireless communication means. Preferably, the flexible circuitry can carry one or more sensors 105. The sensors may include heart rate, blood pressure, blood glucose, or temperature. An outer side of the support can carry more flexible circuitry 107 and sensors 109 for an external environment, sensing parameters such as temperature, humidity, touch or strain. The device can comprise rigid portions and flexible portions. The device may be controlled by user manipulation. The device may include accelerometers and GPS receivers. The flexible circuitry may be separate from the support structure in the form of a sensor, with its own attachment mechanism for attaching the circuitry to an appendage. The support structure may overlay the sensor partially or entirely, or be located adjacent to the sensor. Also claimed is a wearable sensor element in combination with a separate wearable device for controlling the sensor.
