Creating high-tech devices for the study of the brain

(Disponível em português)

 

 
 

At the Champalimaud Centre for the Unknown, a foursome, ages ranging from 27 to 49, is in charge of designing and producing unique, ultra-precise mechano-electronic devices. Without them, the neuroscientists working in the Centre’s research labs would face bigger challenges to carry out many of their experiments.

The objects look like big multicolored flowers – or even giant lollipops. They are actually sophisticated electronic devices. With them, it is possible “to collect, in real time, 200 times a second and simultaneously, the movements, rotations and positions of up to 60 people”, says Filipe Carvalho, the 34 years-old electronic hardware developer who heads the Scientific Hardware Platform (SHP) at the Champalimaud Centre for the Unknown (CCU), in Lisbon, Portugal.

These devices were made by the SHP team for a project, called MESh, imagined by Zach Mainen. Basically, the aim of the project is to measure the synchronization of the movements of a group of people (for instance, as they dance to the sound of music) to gain insight into collective phenomena.

The first test of the system took place in 2016, at the Boom Festival – a feast of alternative cultures held in Idanha-a-Nova, in Portugal. There, the “electronic flowers” (bound to each participant’s head or wrist, or simply held by their “stems”) were used to visualize in real time, on a big screen, luminous projections corresponding to the whirling movements of 30 people on the dance floor.

 

“Flowers” created for the MESh project

 

The system worked “absolutely without a hitch”, says Filipe Carvalho. “For me, this is the most difficult project I have done. It was a nightmarish mix of computers, cables and antennas.”

Interacting with scientists

“Our primary aim is to help scientists create knowledge”, says Artur Silva, a 32 year-old electronic hardware developer also in the team. In 2016, the SHP responded to  more than 200 requests  from CCU neuroscientists. The devices that comes out of their workshop are conceived and produced from scratch.

“A lot of what we do is not easy”, says Paulo Carriço, the 49 years-old mechanic hardware developer of the group, who joined six months ago. One of Paul Carriço’s favorite projects is named Arquimedes, and is being carried out at the request of Rui Costa’s Lab. It is a small lever, for use in mouse experiments, that enables variation, in a very controlled manner (thanks to a mobile weight sitting on the lever), of the pressure that the animal has to apply.

“This lever allows the scientist to determine to what extent the mouse is willing to make an effort in order to get a reward”, explains Paulo Carriço. Still a work in progress, Arquimedes requires the expertise of the whole team and involves, among other things, the production of very small mechanic parts by 3D printing and laser cutting.

 

The lever made for the Arquimedes project

 

How does such a device come into being? “There is a profound interaction between the SHP and the neuroscientists”, replies Filipe Carvalho. “We ask questions that help the scientist to think about what they want and they give us answers that allow us to materialise their idea. And we also seek to understand the scientific problem that motivated the scientist’s request, to be able to suggest, if the opportunity arises, the same type of solution to others. We are a means of communication, a meeting point of information that is scattered among the scientists.”

Esthetic aspects

Artur Silva is the “artist” of the group. When asked if they consider esthetics an important part of their creations, he is the first to answer – in the affirmative.

Obviously, ergonomy and the quality of the devices are the fundamental aspects of their creations – for instance, there cannot be any noise in the circuits nor any sharp corners or edges in the pieces which could harm the animals or the experimenter. But all four agree in saying that, when the technical specifications are met, beauty emerges in the object as a side-product.

And that’s not all: “The fact that an electronic-circuit board looks nice tells us something. If we don’t like it, often it has some underlying technical problem”, says Artur Silva. “Our boards are beautiful”, he insists.

To this, Filipe Carvalho adds that “an out-of-place track [tracks are the electrical connexions engraved on the board’s surface] or a hole that doesn’t have the right size are enough to ruin a whole project”.

And just as the mechanical pieces made by Paulo Carriço out of different kinds of plastic are beautiful, even though that beauty is  essentially due to technical specifications, the circuits designed by Artur Silva and Filipe Carvalho are also appealing to the eyes: symmetric, neat, well-balanced.

Keen sight

Due to the tiny size of the pieces they make, one of the biggest limitations the team has to contend with, to achieve the necessary technical qualities, is their eyesight. Very often, the distance between the electronic components that have to be placed on the circuit boards is less than a millimeter.

This is precisely the thing the fourth member of the team excels at. The youngest of them at 27, Dario Bento, who’s been with the SHP for a little more than a year, literally has linx eyes.

“Before Dario joined us, we had to outsource services to do the pick-and-place part of the job [the positioning of the electronic components on the surface of the electronic boards], explains Artur Silva. “But Dario not only manages to see the circuits without any visual aid, his hand also does not waver either when he is placing tiny amounts of weld at predetermined positions, or installing the component with tweezers.” Dario, the least vocal of them all, fills with pride at these words.

For Dario, the most difficult project in which he left his mark is a movement sensor, designed to be placed on a mouse’s head, that measures only 1.2 cm by 2 cm and has the originality of combining wireless optogenetics with state of-the-art motion sensors in such a tiny device. Optogenetics is a widely used technique which, through the use of light, allows neuroscientists to activate or deactivate specific neurons to study their function or that of the neural circuits to which they belong.

The size and weight of the sensor were also reduced to minimize its impact on the behavior of the mice. Currently, the device weighs 1.8 grams (under 10% of the mouse’s body weight), and during 2017 “we are going to lower it further, to under a gram”, says Filipe Carvalho.

This sensor can also be used to track, in real time, at the rate of 200 times a second, the movements of mice placed in a box in order to measure their behavior. “This kind of recording is usually done with several video cameras, but with this sensor scientists can now quantify, wirelessly and in real time, every movement of the mouse’s head”, adds Filipe Carvalho.

The data collected by the sensor is sent by radio waves to a controller board – which is the second component of this project, codename WEAR. The controller then transmits the data to a computer for real-time or ulterior processing. The third, and last, component is a charger for the tiny batteries included in the wireless sensor – where Paulo Carriço’s plastic pieces shine in fluorescent green.

 

The three components of the WEAR project: wireless sensors, controller board, battery charger

 

“This is, in the world, the smallest, lightest sensor that can record movement, rotation and position in 3D, that allows wireless optical stimulation of the animal’s brain and that has battery autonomy of up to 12 hours”, says Filipe Carvalho.

The team is already at work designing and constructing their next creations, always intent on conceiving unique tools adapted to the scientists’ needs. In the words of Filipe Carvalho, “scientists seek the unknown, and we construct what does not yet exist”.

 

 


 

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Ana Gerschenfeld works as a Science Writer at the Science Communication Office at the Champalimaud Neuroscience Programme

 


 

Edited by: Catarina Ramos (Science Communication Office)
Photos: Courtesy of the Scientific Hardware Platform

 


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