Wear-resistant, hygienic, precise - quickly printed components for Corona test

• What was needed: Gripper for a robot arm
• Manufacturing process: selective laser sintering with SLS powder
• Requirements: Good sliding properties, wear-resistant, consistent precision
• Material: iglidur® i3
• Industry: Medical industry, robotics
• Success through cooperation: Delivery in 24 hours, cost-effective production of customised parts, lubrication-free operation

The application at a glance:
For an automated drive-in corona test station, the service company BoKa Automatisierung GmbH needed a gripper for its robot arm that precisely dispenses the test tubes to the test subjects. The gripper should be able to be operated continuously to enable as many automated tests as possible. The speed of the SLS process and delivery within one day at the Cologne site were the decisive criteria, which is why the company decided to work with igus®. In addition to the high abrasion resistance, the components also impressed with the solid lubricants contained in the high-performance polymer, which fulfil the hygienic requirements of such a test station.

During the coronavirus pandemic, testing for suspected infections has become the norm. The young industrial services company BoKa Automatisierung GmbH from Dorfprozelten has developed an automated drive-in coronavirus testing station ("DriCo-Mate") to protect medical staff from infection and reduce their workload. A gripper was needed for the six-axis robot arm, which dispenses the test tubes to the test subjects and picks them up again, to guarantee smooth operation over a long period of time.

Thanks to the comparatively high speed at which components are manufactured in the SLS process, igus® was able to present a prototype for the robot gripper in a very short time. At the same time, the high-performance plastic iglidur® i3 proved to be a suitable material for the gripper, as it is wear-resistant and therefore guarantees a long service life despite heavy use. In addition, iglidur® i3 impresses with its self-lubricating specifications, which mean a better standard of hygiene for the test station.

The test subjects drive to the test station by car. There, they are guided through the process step by step with video instructions. The ID card is scanned and hand sanitiser is dispensed. The station then assigns the test person's personal data to a test tube using a barcode. This is where the six-axis robot arm with gripper comes into play: it hands over the tube for independent sampling. This can be monitored by a healthcare professional via camera transmission so that the test can be utilised. Once the swab has been taken, the user puts the tube back and the gripper stores the tube until it is transported to the laboratory. This contactless automation protects medical professionals from infection and reduces the workload for staff. According to BoKa, a test procedure takes around four to six minutes. The test system can be operated by two people at the same time and can collect around 500 samples within 24 hours.

Especially in the current global pandemic, it was important to manufacture and deliver the prototype for the gripper quickly in order to present the test station to medical institutions and authorities. The speed of the SLS process and delivery within one day at the Cologne site were the decisive criteria, which is why the company for robotic systems in the collaborative sector decided to work with igus® GmbH. At the same time, the cost-effective production of the customised grippers was convincing. In comparison to milled parts, the robot grippers are produced using 3D printing without tools, i.e. without additional set-up costs.

Given around 500 test subjects in 24 hours, the robot gripper is subjected to constant load and movement. iglidur i3, a wear-resistant 3D printing plastic, allows these movements to be performed easily while retaining gripper precision over time. The material was developed specifically for manufacturing friction-sensitive parts, and its abrasion resistance is up to 50 times that of other plastics. The SLS process can be used to precisely adapt and manufacture the high-performance polymer to customer requirements. At the same time, the material exhibits great stability in use.  The solid lubricant embedded in the plastic allows operation without external lubrication, contributing to an improved testing station hygiene standard.