Finger Flexion and Extension Driven by a Single Motor in Robotic Glove Design

Abstract

Pneumatic and tendon‐driven actuators are widely used in soft robotic glove design. Tendon‐driven robotic gloves are generally better in controllability, dexterity, and force output, but they are less comfortable than pneumatic ones. Most soft gloves focus on only one actuation mode where either motor‐driven tendon or pump‐driven pneumatic transmission is used. Herein, a double‐acting soft actuator (DASA) that provides both tendon‐driven flexion and pneumatic extension of fingers by a single motor is presented. This is achieved by a smart pulley and bellow system. The kinematic model of the tendon‐driven flexion and the torque model of the fabric‐based pneumatic extension actuator (FPEA) are developed to analyze the DASA performance. The bending angle of the index finger actuated by the tendon and the FPEA extension torque of a joint are characterized by experimental studies. A cycle test of the DASA is conducted 3000 times, demonstrating its high repeatability. A prototype soft glove (68 g) based on the proposed DASA with a control box (835 g) is fabricated to demonstrate finger flexion and extension assistance. Based on electromyography signals, the performance of the robotic glove is evaluated by a squeezing sponge test.

3D-printed passive bellow actuator for portable soft wearable robots

“…The glove features five finger actuators based on PBAs, which are mounted on a rigid base. The size of the glove is designed based on the average hand size of adult males, and the length of each PBA finger actuator is tailored to match the actual length of the fingers [30]. Figure 6(a) displays the 3D model of the soft robotic glove in both open and closed states.…”

Finger joint aligned flat tube folding structure for robotic glove design

“…Besides, the bulk volume and unsightly appearance of the hand exoskeletons severely restrict their applications and reduce the desire of users. Inspired by human tendons, the biomimetic tendon-driven actuation method is widely used in designing robotic gloves as shown in figure 1(b) [15][16][17][18]. Compared with hand exoskeletons, robotic glove based on tendon-driven actuation has low weight and looks like normal gloves that could avoid stares from strangers in ADL.…”

Lightweight Soft Robotic Glove with Whole-Hand Finger Motion Tracking for Hand Rehabilitation in Virtual Reality

“…In addition, the bulky actuators on the fingers may cause interference between fingers upon actuation. In contrast, the motor-tendon driven method is much lighter, where a small motor can be connected to the fingertip via a tendon and the finger can be driven by the rotation of the motor [ 7 , 8 , 9 ]. This method has a much simpler glove design, which makes the hand-wearable part more comfortable and lighter.…”