Soft Manipulation

We develop customizable soft manipulators, including pneumatic chamber-gripper devices that generate compliant actuation and can be very useful in the process of gripping delicate tissue, and soft robotic hands that be used for tele-operated delicate manipulation in harsh environments.

Soft Surgical Gripper

Traditional hard tissue grippers are limited in handling delicate soft tissues during surgery, particularly due to the high stress points that are generated on the soft tissue during gripping. In this study, customizable soft pneumatic chamber–gripper devices were designed to provide compliant gripping, so as to replace conventional tissue grippers such as the laparoscopic grasper or forceps in delicate tissue manipulation. The soft chamber–gripper device involves very simple design and control to generate actuation. It is fabricated from an elastomeric material using a modi- fied soft lithography technique. The device consists of a gripper component that can be made up of one or more gripper arms with a pneumatic channel in each arm, and a chamber filled with air. The pneumatic channels are positioned close to the outer wall of the gripper arms and are connected to the chamber. Upon compression of the chamber, the pneumatic channels will inflate towards the outer walls, which thus bends the gripper arms and results in a closed gripping posture. This soft chamber–gripper device can be used to pick up objects of size up to 2 mm with a compressive force that is more than three times smaller than the grip force generated by traditional forceps. This will be useful in preventing tissue trauma during surgical manipulation, especially in nerve anastomosis.
Relevant Publications:
  • J.H. Low, I. Delgado-Martinez, C.H. Yeow. "Customizable soft pneumatic chamber-gripper devices for delicate surgical manipulation." ASME Journal of Medical Devices 2014. 8(4), 044504.

Soft Robotic Hand

Traditional actuators are usually heavy, expensive and require a complex multi-component mechanical structure to generate human-like movement. Therefore, we proposed a lightweight soft finger actuator (25g) that is powered by pneumatic means to perform the grasping tasks. The soft actuators were fabricated using 3D-printing and soft lithography techniques. Three finger actuators were used to create a prosthetic hand, which is capable of grasping and holding objects with different sizes and weights up to 600 g. These studies showed the possibility of deploying these soft finger actuators in performing grasping tasks.
Relevant Publications:
  • J.H. Low, M.H. Ang Jr, C.H. Yeow. "Customizable Soft Pneumatic Finger Actuators for Hand Orthotic and Prosthetic Applications", 14th IEEE/RAS-EMBS International Conference on Rehabilitation Robotics (ICORR 2015).