Impact of 3D Printing Technique and TPE Material on the Endurance of Pneumatic Linear Peristaltic Actuators.

Miranda Fateri,Udo Grabmeier,Constantin Schuler,Fernando Gomes De Almeida,Tobias Walcher,João Bravo Pinto,Michael Salinas,João Falcão Carneiro

doi:10.3390/mi13030392

Abstract

In this paper, additive manufacturing was used in order to produce hose prototypes for peristaltic linear pneumatic actuators. In order to optimise the endurance of the actuator, we 3D printed different thermoplastic polyurethane elastomers with different shore hardness levels using ARBURG Plastic Freeforming technology. Furthermore, effects of the hose geometries on the lifetime of the actuator were investigated. Experimental evidence showed that the lifetime of the actuator was dependent on the combination of the hose design and on the material used to manufacture the hose. Moreover, experimental tests showed that the use of the Aurburg-Freeformer 3D printing technology led to a much higher hose endurance than the one reported by using the fused layer manufacturing technique.

Highlights

Several approaches have been followed, namely, by (i) using flexible materials [4–10] to embody the actuator, (ii) using hybrid electric-pneumatic actuators that combine the simpleness of control of electrical actuators with the pneumatic actuators low stiffness [11,12], and (iii) developing a new piston configuration to increase the energetic efficiency of conventional cylinders [13]
Two types of thermoplastic polyurethane elastomer (TPE) were used for printing different designs
The 60 mm stroke hoses were experimentally tested for the 3D printed hoses in a peristaltic linear pneumatic actuators (PLPA) setup

Summary

Introduction

Interest in development of interactive robots capable of co-working and interacting with humans is gaining significant attention from different industries in recent years. PLPA can be used to perform curved profiles, can be manufactured with low cost, and can be built with very long strokes These characteristics, along with a favourable friction behaviour for servo control applications, make them very attractive in comparison with conventional pneumatic actuators. PLPA suffers high mechanical stresses, as they are both compressed between the rollers and extended by the inner pressure These mechanical constraints result in reduced endurance of the actuator, making them not suitable for industrial applications at their current stage of development. Investigations using FLM of TPE (shore hardness of 82 A) have shown that geometries with geometrical reinforcement at the folded area can increase the average endurance of the hose more than twice when compared to a circular design [17].

Material

Pneumatic Test Bed

Procedure

Results and Discussion

Conclusions