A Delicate but Firm Touch

Compliant mechanisms are already being used in medical devices, primarily in single-use throwaways and clamps of various types. Most of these devices employ a “lumped” compliant joint that bends in a very controlled and stable way and most are intended to be disposed of instead of sterilized for future use. The lumped compliance gives the device a high degree of accuracy and it does so by concentrating a lot of strain in a small envelop of motion. This usually limits their use to applications that do not damage soft tissues.

By distributing compliance over the whole mechanism, a tissue friendly manipulator can direct very specific and carefully defined gripping strength for surgery at macro- and micro scales but afford enough flexibility to not damage the tissue. They are also flexible enough to access difficult surgery targets with minimum invasion of surrounding areas . A complex geometry monoform can be produced inexpensively to grasp and hold tissues without injury for long periods and then be disposed of as appropriate.

Flexible but Strong

In addition to surgical instruments, compliant joint prosthetics can be devised to mimic the elasticity of connective tissues that are naturally both strong and flexible. By applying distributed compliance carefully, and often in multiple complimenting directions, even a complex motions such as wrist-action is possible in a strong, resilient and cost-effective design.