Smart robots to make smaller chips

A robotic arm in a factory that repeatedly performs the same movement: that’s a thing of the past, argues Ming Cao, Professor of Networks and Robotics and Director of the Jantina Tammes School of Digital Society, Technology and AI. ‘We’re moving towards smart industry, with robotic arms that are able to make decisions.’ Various researchers at the University of Groningen are collaborating with high-tech companies such as chip manufacturer ASML to make production processes more autonomous.

FSE Science Newsroom | Charlotte Vlek

‘Manufacturing a chip is a fully automated process,’ Cao explains, ‘there is very little human interaction involved.’ But our electronic devices can do increasingly more while becoming smaller and smaller, which means that chip production has to become even more accurate at a tiny scale. And that means that the machines that produce chips need to be finetuned to compensate for small changes in temperature or humidity in the factory. Cao: ‘Such a thing is beyond human capabilities. But a sensor is able to pick up miniscule changes instantly.’

Obtaining a flat silicon wafer

For example, consider the material that forms the basis of a chip: silicon. A flat strip of silicon, called a silicon wafer, is placed under a laser beam that transfers layers of interconnected patterns onto the wafer at a nanoscale. It’s of great importance that the silicon wafer lies completely flat, because as soon as the laser hits the surface at an angle, the laser bundle goes out of focus, causing inaccuracies.

That’s why Bayu Jayawardhana, Professor of Mechatronics and Control of Nonlinear Systems, and Mónica Acuautla Meneses, associate professor of Engineering Materials for Mechatronic Systems, have teamed up with chip manufacturer ASML to develop a deformable wafer table on which the silicon wafer can lie completely flat. To do this, they use a piezo material that expands at a specific location when a voltage is applied to it. This allows each part of the wafer table to be adjusted as required.

Getting all parts to work together

The wafer table is just one part of a machine that makes the chip. Such an element might be developed by an expert on piezoelectric materials, whereas another expert might provide the required control algorithms. But how do you ensure that all these different experts develop elements that actually contribute the right things to the system?

Bart Besselink, associate professor in Systems and Control, is working on mathematical methods that can specify the elements of such complex systems. ‘These could be complex systems such as machines in a chip factory, but also a self-driving car, or a smart energy system,’ Besselink explains. ‘The core idea is to formulate in a mathematically precise way what specifications each element must meet.’

‘An engineer at ASML may know from experience that a particular part of machine will only function well under certain circumstances, but we bring automation into the design process.’ This facilitates discussion between various design teams, and they may even be able to negotiate which requirements are absolutely necessary, and which requirements can be relaxed.

Collaborative robots

Ming Cao is also exploring how multiple elements can work together. ‘For example, consider robots that assemble a product: one gathers the necessary components, while the other puts them together. In such a case, it would be helpful if they could exchange information: if the first robot already knows the weight of a component, it could then share this information with the next robot.’

‘But it’s just like with humans,’ Cao adds: ‘there needs to be mutual trust to be able to collaborate.’ Because what if a neighbouring robot’s information does not match their own measurements? That is when Cao’s robots will start negotiating with each other, and they will do so in milliseconds: ‘These are complex situations that need to be evaluated in a short time, with little room for error. Just like multiple robotic arms that work together in a factory.’

High on the autonomy ladder

Cao, Jayawardhana, and Besselink are all working on autonomous systems in industrial applications. This way, they want to bring innovation to Dutch industry. They will soon do this through a new ecosystem in the north of the Netherlands: Infinitech, which brings together questions from industry and solutions from academia.

Jayawardhana gives an example: ‘Imagine the various levels of autonomy as a ladder. A car with cruise control is just one small step on the autonomy ladder, while a self-driving car is at the top of the ladder. We want to take companies as high as possible on this autonomy ladder. There are so many beautiful ideas; the key question is what applications they can be used for.’

In September 2024, the University of Groningen will start the new Engineering Doctorate in Autonomous Systems. Trainees will work at a company as well as at the UG to develop technical solutions for the automation of systems in the high-tech industry.

Read also: 'The chip of the future' (appears next week)