An interest in the practical component of physics during secondary education led Carolina Antunes to choose a bachelor’s degree in Physical Engineering at Instituto Superior Técnico. However, throughout the course, her enthusiasm for electronics grew due to her contact with curricular units in this field.

In the summer between the second and third years of the programme, she chose to undertake an internship at the Laboratory of Experimental Particle Physics Instrumentation, where she contributed to the characterisation of power supplies for the ATLAS photomultipliers, one of CERN’s main particle detectors. “This internship already brought together elements of electronics — the power supplies — and physics,” highlights Carolina Antunes.

It was through this experience that she became certain she should follow a path integrating an electronics component, leading her to pursue a Master’s degree in Electrical and Computer Engineering with a specialisation in this area. “I haven’t yet met anyone who has followed the same path,” she notes.

[At INESC-MN] I started with sensor characterisation and then moved on to integrating them into a circuit, but I needed electrical engineering knowledge that I didn’t gain during my bachelor’s degree (…) in order to combine a physical phenomenon and turn it into a circuit.

Carolina Antunes, Master’s student in Electrical and Computer Engineering

After some research, she found the opportunity to undertake an internship at INESC-MN, working on triboelectric research. “I had absolutely no idea what it was,” she recalls. “I discovered that they were systems that could function as energy harvesting devices: they don’t need an external energy supply but can collect signals through contact. Two surfaces come into contact and, when they separate, create an electrostatic field through which they can generate electrical current.” In this way, the physical principle of induction is applied to an electronic circuit.

One possible application of triboelectrics, in this context, is energy storage in pacemakers, with the aim of increasing device autonomy and reducing the need for surgical interventions. In this case, energy can be generated through repeated contact between surfaces as a result of body movements, such as breathing. This system may also be applied to other scenarios, particularly when operating under extreme conditions that do not allow battery replacement.

On the other hand, triboelectrics can also be used for motion monitoring. In this case, point contact between surfaces creates a charge which, in turn, generates a measurable signal, allowing data to be obtained on the force applied during contact, as well as on the current or voltage across the load. Although energy is not stored, this system can be used to study both human body movements and machine operation, in order to assess whether they are functioning correctly.

The sensors are being used for wearables; in this case, the application is biomonitoring. We use a shirt with sensors placed at specific points, and whenever there is movement, contact occurs between the two surfaces and charge is transferred, producing a signal that is measured.

Carolina Antunes, Master’s student in Electrical and Computer Engineering

The student explains that the shirt contains sensors in locations such as the sleeve, with the aim of monitoring arm movement. In this way, it becomes possible, for example, to determine whether the arm is bent, based on the correspondence between movement and the activated sensors.

It was this application that Carolina Antunes focused on for her undergraduate integrated course project (PIC1). “I started by characterising the sensors and their relationship with force. In the integrated project, I tried to implement wireless communication,” she explains. She also had the opportunity to follow the thesis of Ismael Domingos, PhD in Electrical and Computer Engineering, which focused on communication between the sensors and the system via Bluetooth. However, this type of communication requires batteries. In order to obtain a more energy-efficient system, Carolina Antunes decided to study the use of radio frequency, a type of wireless communication that does not require batteries. During the PIC, she carried out only simulations; nevertheless, she was able to obtain software and measurable results. After completing her bachelor’s degree, she continued working at INESC-MN and is currently testing the integration of the sensors into the system.

What I want is to develop systems that are more efficient and more autonomous. Triboelectrics are an example of this: they don’t require much energy and aim to be as efficient as possible.

Carolina Antunes, Master’s student in Electrical and Computer Engineering

Considering the growth in energy consumption, sustainability is, for Carolina Antunes, a priority: “Nowadays everything is increasingly digitalised; we need more technology, and if we continue with the level of consumption we have today, we won’t have enough energy for everything,” she stresses.

Technological evolution also requires an ever-growing number of professionals specialised in areas such as electronics. “In a technological advance that demands more and more ideas, we need many more people,” she states. “Especially in the microelectronics course unit (…) I realised how important this area is today,” she adds, referring, for example, to chip production and the technology required for the process. From a future perspective, Carolina Antunes would like to contribute to the creation of sustainable, disruptive systems with social impact: “I would like to be part of a high-tech team, working on cutting-edge technology, developing something that would change the way we live. (…) Twenty years ago, we probably wouldn’t have expected to have a mobile phone in our pocket that was also a computer, and today we can’t even imagine not having one.”

In addition to academic success, her enthusiasm for contributing to a better future was the main reason for being awarded the “Women in Energy MSc” scholarship by TagEnergy. She sees this scholarship as recognition of the work she has developed and as motivation to continue working in this field. The initiative aims to promote the role of women in scientific areas related to energy.

This scholarship gives me the motivation to continue studying, even though it is an area with relatively low female representation. Our contribution is extremely important — our ideas are worth it.

Carolina Antunes, Master’s student in Electrical and Computer Engineering

Although both physics and electronics are currently male-dominated fields, Carolina Antunes emphasises that she has never felt inferior for being a woman. In addition to internships, she also has experience as a teaching assistant and highlights that her work has always been recognised, as demonstrated by students’ interest in her classes. “Now, in electrical engineering, I feel some pressure because I feel I am representing the female group, but this is also a motivation. I want to show that I can succeed, have good ideas, carry out my research and, hopefully, have an impact in this field,” she says.

After reflecting on her journey, when asked what she would say to her 18-year-old self, Carolina Antunes says she would advise herself to explore in order to discover new perspectives and career paths. “I didn’t really know what I wanted to do in secondary school, and I’m still discovering new things today,” she notes, leaving a reflection that also applies to many students finishing compulsory education.

I would say: try things out. (…) It’s important to explore, not be afraid and look into new areas.

Carolina Antunes, Master’s student in Electrical and Computer Engineering