Figure 1

Structure, manufacturing and working principle of the DEA-based robotic mixer. (A) Photo of the device, showing the double-cone soft actuator (upper part) and its driving electronics (lower part), held in place by five screws, which were used to vary the actuator’s bi-axial pre-strain, so as to change its performance (see text). (B) Step-by-step manufacturing process of the double-cone soft actuator: an elastomeric membrane is radially pre-stretched and clamped to a circular frame; a coating mask is applied on it; a conductive material is deposited over the mask, producing four independent compliant electrodes; two electroded membranes are finally joined together at the centre, axially stretched (so as to achieve the double conical shape) and kept in place by the screws. Details are reported in “Methods” section. (C) Working principle of the device, schematically shown with top and side views; red colouring of an actuation sector indicates its electrical activation. (D) Examples of two activation sequences, where either one (top) or two (bottom) sectors are electrically activated at the same time.