Various sensors and methods of assembling sensors are described. In some embodiments, the sensor assembly includes a first end, a body portion, and a second end. The first end can include a neck portion and a connector portion and the second end can include a flap, a first component, a neck portion, and a second component. A method is also described for sensor folding. The method can include using a circuit with an attached emitter and a detector that is separated by a portion of the circuit. The method can also include folding the portion of the circuit such that a first fold is created through the emitter and folding the portion of the circuit such that a second fold is created such that the first fold and second fold form an angle.
