... Consequently, most works described in this section are not necessarily portable at the moment of publication, but have clear opportunities to lately become HMP-WDs. Starting from prototypes that cover a small skin surface, there are bracelets (Figure 4a), designed to be worn on the wrist (see, e.g., in [19,21,59,60]); gloves and mobile device mockups (Figure 4b), designed to be worn or held on the hands (see, e.g., in [37,[61][62][63][64]); belts (Figure 4c), designed to be worn surrounding the body from the chest to the abdomen (see, e.g., in [8,35,41,42]); and jackets ( Figure 4d), designed to be worn on the upper body with actuators usually located on the back, the front and the superior limbs (e.g., [38,65]). Other variations are whole body suits [15], and headphone type displays [39], but instances are scarce. ...