Figure 10.

(A) Simulation of the freeform optical sensor illuminating the sample; (B) Photograph of freeform sensor and cylindrical lens array; (C) Freeform optical set up illuminating a metal sample. (D,E) Representation of the splitting and diverging process of freeform optical sensor. Reproduced from [29], with permission from SPIE © 2015; (F) Photograph of the fiber optic vibration sensors. Reproduced from [30], with permission from SPIE © 2016; (G) Drawing of planar optronic sensor system. Reproduced from [31], with permission from Elsevier Ltd. © 2015; (H) User inputs such as push (a), rotation(b), linear movement (c), and acceleration (d) can be sensed by the displacement of a 3D printed light guide. Reproduced from [32], with permission from ACM © 2012.