Twisted and coiled polymer muscle actuated soft 3D printed robotic hand with Peltier cooler for drug delivery in medical management

Abstract

Many robotic hands have been proposed to have unique designs and capabilities, focusing on sensing, actuation, and control. This paper presents experimental studies on a soft 3D-printed robotic hand whose fingers are actuated by twisted and coiled polymer (TCP<sub>FL</sub>) muscles, driven by resistive heating, and cooled by water and Peltier mechanism (thermoelectric cooling) for increasing the actuation frequency. The hand can be utilized for pick and place applications of drugs in clinical settings, which may be repetitive for humans. A combination of ABS plastic and thermoplastic polyurethane material is used to additively manufacture the robotic hand. The hand along with a housing tank for the muscles and Peltier coolers has a length of 380 mm and weighs 560 gm. The fabrication process of the TCP<sub>FL</sub> actuators coiled with 160 µm diameter nichrome wires is presented. The actuation frequency in the air for TCP<sub>FL </sub>is around 0.01 Hz. This study shows the effect of water and Peltier cooling on improving the actuation frequency of the muscles to 0.056 Hz. Experiments have been performed with a flex sensor integrated at the back of each finger to calculate its bend-extent while being actuated by the TCP<sub>FL</sub> muscles. All these experiments are also used to optimize the TCP<sub>FL</sub> actuation. Overall, a low-cost and lightweight 3D printed robotic hand is presented in this paper, which significantly increases the actuation performance with the help of cooling methods, that can be used in applications in medical management.

HBS-1.2: Lightweight Socially Assistive Robot with 6-Ply Twisted Coiled Polymer Muscle-Actuated Hand

“…TCP actuators are suitable for tasks which do not require a high-response frequency. Employing active cooling methods, such as fan cooling and liquid cooling or Peltier cooling, is a good choice to improve the response speed [30][31][32]. Future works should concentrate on improving the cooling speed.…”

Single layered soft skin actuated with twisted and mandrel coiled actuators for soft robotics

“…Lamuta et al 38 showed soft morphing skins creating digital texture patterns. In order to increase the actuation frequency of the electrothermal TCP actuators Singh et al 39 introduced the Peltier coolers for improving the actuation frequency of the TCP FL actuated robotic hand. Earlier, Besse et al 40 demonstrated a flexible active skin with large reconfigurable arrays of shape memory polymer actuators.…”