An Anthropomorphic, Coupled-Adaptive, Lightweight, Dexterous Hand with Integrated Three-axis Tactile Sensors: Towards Prostheses with Dexterous and Stable Grasping Capabilities

One of the most intriguing problems is using a dexterous hand prosthesis to replace a lost hand. Physical characteristics of the hand, such as poor functionality, loss of tactile sensation, and excessive weight, limit the use of state-of-the-art dexterous hand prostheses. Here, we introduce a novel dexterous hand designed to get beyond these restrictions. The dexterous hand adopted a novel link-driven coupled-adaptive underactuated finger mechanism and has both adaptive and coupled motion characteristics. The coupled-adaptive underactuated fingers can adaptively envelop grasping objects of different shapes and sizes. And the little and ring fingers are driven by a single actuator with a differential mechanism. Therefore, the hand can perform the majority of the grasps and motions needed for everyday living tasks with just five electric motors. Its design closely mimics human anatomy, matching an adult hand in dimensions, weight (410 g), and functional capabilities. The device delivers a peak force of 25 N at the thumb and 18 N at the remaining fingertips, with a rapid closing time of under 0.4 s. Furthermore, the dexterous hand integrates a three-axis tactile sensor for five fingers. It endowed the hand with slipping detection, self-grasping force adjustment ability, which will enhance the grasping stability and significantly reduce muscle fatigue. As a result, this study achieves a biomimetic prosthetic hand that excels in both performance and lifelike resemblance.