Custom specimen racks can be 3D printed and mounted to the workstation for the cobot to pick from. (Credit: Instron)

A collaborative robot, or cobot, is an automation tool that can be adapted for use in mechanical testing laboratories. Cobots are robotic arms designed to work alongside humans and are adaptable to a variety of applications. They are intended to bridge the gap between manual system operation and full industrial automation, offering the benefits of automation without the additional complexity of a fully robotic testing system. Cobots are particularly suited for use in the biomedical industry, where full-scale automation is often not possible but where lab efficiency, safety, and data integrity are critical.

Cobots and robots can perform very similar tasks: Both are designed to remove a system operator from a task or operation by automating part or all of the testing process. Because of the overlap in functions, both options can be appropriate for a given application; however, there are some key differences that make one solution preferable over the other in certain circumstances.

Robot systems are best suited for repeating the same task at a high speed for 24/7 operation. These systems are not always equipped with force control features and struggle with tasks that require varying degrees of sensitivity. Because these robots are designed for high speed, the possibility for damage or injury is high if these systems are not properly implemented. Making changes to the movements of the robot or adding a new task requires someone with a robotics or software engineering background to implement.

Cobots are generally more flexible and easier to use than robots. The average cobot will operate at a lower speed with a smaller reach and lesser payload than an averag robot. It will also typically have a smaller footprint and be more lightweight than a robotic system.

Cobots come equipped with software that makes changes to movements and tasks easy. Anyone with basic programming experience will be able to make changes quickly and efficiently, and the learning curve to make changes to the software is much less steep than it is with the average robot.

The cobot’s light weight makes it easy to transport or relocate within a facility. In terms of safety, the force-controlling sensors greatly reduce the risk to operators or devices, and depending on the risk of the particular task, a cobot may be able to operate with no physical guarding.

Lab Efficiency

Most mechanical testing — particularly biomedical and medical device testing — is performed manually. A lab employee sets up the initial test and then loads and unloads individual specimens until the sample batch is completed. In this time-consuming process, many tests take between 3 and 5 minutes to complete while only requiring about 30 seconds worth of operator interaction per test. For example, if a test takes 3.5 minutes to complete, a test frame can run a batch of 30 specimens in 2 hours. A technician is required to be present for this entire period, while only needing to interact with the system for a total of 15 minutes in order to load and unload specimens every 3.5 minutes. This inefficient process presents an enormous opportunity to recoup lost time, especially as high-value, expensive labor resources are frequently responsible for running the testing in many biomedical testing labs. Freeing up the operator to perform other valuable tasks would bring significant benefits to the lab.

Cobots can be added to a new or existing universal testing system to automate the loading and unloading of specimens while the system performs tests without the operator present. (Credit: Instron)
A cobot mounted on an autoinjector testing system capable of performing all required testing of injection devices in a single test. (Credit: Instron)

Many medical device companies could benefit from automation but are not a good fit for a fully automated robotic system. Companies might not need a fully automated system if, for example, their test volume isn’t high enough to warrant a robotic system because they require a system with more flexibility. For labs where fully automated testing is not possible or desirable, cobots offer a promising new solution.

Safety and Ergonomics

When using a cobot, the operator is not required to load and unload specimens by hand into the frame, greatly improving ergonomics by reducing repetitive movement. When testing high-risk items such as syringes with needles, cobots also improve safety by reducing sharps handling by the system operator. In order to completely eliminate the need for the operator to handle sharps, systems can be configured with a tap removal.

Cobots also have an advanced control system designed to reduce the risk of injury to the test operator and damage to the cobot or its surroundings. The force on each axis is constantly monitored, and the cobot will stop if it comes in contact with an unexpected object. Guarding, or protective shielding, for the cobot is dependent on the application and the specific risks associated with moving and testing the specimen. For example, a cobot testing syringes with exposed needles will likely require different guarding than a system performing residual seal force testing on vials.

Data Variance and Integrity

Data spread between operators is a common issue in medical testing. Each person loads specimens into the test system in a slightly different way, which limits repeatability. Adding alignment devices can improve this issue but cannot fully eliminate it. The cobot removes any variance in specimen loading. Most cobots are repeatable to within a fraction of a millimeter, which yields results that are vastly more repeatable than those from a system being manually loaded. Additionally, any time an operator is manually transferring data between a testing system and a production database presents the possibility for errors to be made. By using a cobot system to automate that transfer, human error can be removed.

Test Applications

Autoinjector Testing. Manufacturers of autoinjectors and other needle-based injection systems are ramping up production to meet the rising global demand for safe and convenient forms of drug delivery. Bringing these devices from development to production is a long process with strict requirements for both functional and usability testing of the devices at each of stage of product development. A test frame with cobot automation is ideal for testing various design iterations of a product with minimal changeover time, reducing the burden on highly technical design engineers to stand in front of a system. Technicians can simply place the test specimens in the system’s production tray and the cobot will load and unload them while the machine runs the necessary tests.

Syringe Testing. Break-loose and glide-force testing constitutes the bulk of syringe testing and is used to determine the real-world forces required to operate the syringe. Pre-filled syringes are combination devices requiring device verification testing before a New Drug Application can be submitted. For syringe testing applications, cobots can be placed separately or in-line to improve throughput and efficiency. Fully integrated manufacturing systems can even use measured break/loose glide force data to modify production settings in real time to correct for any out-of-tolerance values.

Luer Connector Testing. ISO 80369 is the global standard used by device manufacturers to evaluate the mechanical and pressure-related properties of the connections. When used in conjunction with a torsion-enabled universal testing system, a cobot can be extremely beneficial for lab productivity, essentially functioning as a pick-and-place operation to reduce operator influence.

The repeatability of automated specimen insertion is also ideal for improving device alignment, a significant contributor to data spread. Since luer connections can be found on a wide array of devices, the sample racking can be customized to accommodate all potential device geometry.

Bridging the Automation Gap

Cobots present new automation solutions in a variety of potential applications. They offer flexibility and ease of use that isn’t possible with traditional robotic automation systems. For the biomedical industry, a cobot installed on a mechanical testing system can greatly improve lab efficiency, operator safety, and data variance and integrity. Cobots are particularly well suited for test labs that are looking to improve efficiency but do not have high enough testing volumes to justify the purchase of a fully robotic system. These devices are also suitable for labs that see a high changeover in testing needs and fixturing.

This article was written by Richard Spiegel, Product Manager, Instron, Norwood, MA. For more information, visit here . Contact: This email address is being protected from spambots. You need JavaScript enabled to view it..