An analytical model for the design of Peano-HASEL actuators with drastically improved performance

High‐Strain Peano‐HASEL Actuators

“…We introduced an electrohydraulically driven, linearly contractile soft actuator which achieved linear strain exceeding 20% (the typical value for skeletal muscle). Specifically, the HS‐Peano‐HASEL actuator introduced in this paper achieved maximum linear strains of ≈24%, exceeding the maximum strain of ≈15% of Peano‐HASEL actuators . Material and design variations were utilized to improve the stroke of multiunit HS‐Peano‐HASEL actuators.…”

“…The zipping region and the contraction region are therefore aligned in the direction of contraction. Thus, the zipping region contributes to the initial length of the actuator but does not contract during actuation, and consequently the maximum theoretical actuation strain of Peano‐HASEL actuators is limited to 24% . In HS‐Peano‐HASEL actuators, the zipping regions and the contracting region are aligned orthogonally to the direction of contraction, and therefore do not contribute to the initial length (Figure a).…”

“…Specifically, the HS-Peano-HASEL actuator introduced in this paper achieved maximum linear strains of ≈24%, exceeding the maximum strain of ≈15% of Peano-HASEL actuators. [29,30] Material and design variations were utilized to improve the stroke of multiunit HS-Peano-HASEL actuators. The demonstration of the ACM highlights potential applications in artificial organs [40] and soft pumps.…”

“…Thus, the zipping region contributes to the initial length of the actuator but does not contract during actuation, and consequently the maximum theoretical actuation strain of Peano-HASEL actuators is limited to 24%. [29] In HS-Peano-HASEL actuators, the zipping regions and the contracting region are aligned orthogonally to the direction of contraction, and therefore do not contribute to the initial length ( Figure 1a). For that reason, HS-Peano-HASEL actuators can achieve a maximum theoretical actuation strain of 36% (see the Supporting Information for calculation).…”

“…Peano‐HASEL actuators, one type of HASEL actuator, exhibit fast and precise linear contraction that closely resembles the movement of natural muscle, and they are predicted to exceed the energy density of muscle; therefore, they are well suited as actuators in bioinspired and biomimetic systems. However, the maximum theoretical strain of Peano‐HASEL actuators is 24%, and only ≈15% strain has been demonstrated experimentally, while natural muscle typically operates at 20% strain and achieves maximum strain of up to 40% …”