Dr. David Zarrouk, Director of Bioinspired and Medical Robotics Laboratory – Interview Series

David is a a Senior Lecturer (assistant professor) at the ME department of Ben Gurion University of the Negev, and director of the Bioinspired and Medical Robotics Laboratory. His interests are interests are in the fields of biomimetics, millisystems, miniature robotics, flexible and slippery interactions, space robotics, underactuated and minimally actuated mechanisms and theoretical kinematics.

What is it that initially attracted you to the field of robotics?

Since my childhood, I was always fascinated with machines. I always tried to build them and eventually after graduating with my BSc in Mechanical Engineering, I’ve been thrilled to be able to focus on developing robots at Ben-Gurion University of the Negev that can crawl inside the body.

You have Ph.D. in medical robotics. What are some of the types of medical robotic applications that have you the most excited?

Any application that involves precision that can be programmed is a possible candidate for a robotic solution. Two robots I worked on in the past involved those that crawl inside the body and performing brain surgeries using needles.

One robot you created is called The Flying Star which is a hybrid Crawling and Flying Robot. What was the inspiration behind this robot?

The sprawl mechanism of the STAR robots is inspired by insects but includes wheels which combines the advantages of bio-inspired creatures and wheeled vehicles.

What were some of the challenges behind building The Flying Star?

The Flying STAR is not a regular quadcopter as it changes the orientation of its wings which influences it general control dynamics. The different design variables were challenging at the beginning and the transition between flying to driving modes required unique parts which we had to develop by ourselves.

I was impressed with how versatile The Flying Star is, it can literally dodge obstacles, crawl beneath them, fly overhead them, etc. Can you discuss how The Flying Star makes the decision on which mode of transport to use? How does it choose whether to crawl underneath an object or fly overtop?

The flying STAR is initially designed for search and rescue purposes and for last mile package delivery. We are developing algorithms to determine how when to fly or to drive based on distances and energy requirements but also on the shape of the obstacle. The decision algorithm, which are still being developed, will be based on camera mapping of the surrounding. If an opening is high enough to crawl underneath it, the FSTAR will simple drive through it. Otherwise, it will fly. A human operator may still be needed in challenging confined spaces (such as rubble).

My first impression when I saw the video for the Minimally actuated Reconfigurable Continuous Track Robot, is that with a camera at its helm it would be perfect for search and rescue. What are some use cases that you envision for such a robot?

The reconfigurable continuous track robot is primarily developed for search and rescue purposes in difficult terrain such as rubble. But it can also be used for other applications such excavation, agriculture and crawling inside pipes for industrial maintenance.

One of your previous projects is SAW, a Minimally actuated Reconfigurable Continuous Track Robot. What was the inspiration behind this robot?

The SAW (single actuator wave) robot was originally inspired by miniature biological organism which swim by undulating their tails. Creating this robot was very challenging. Although the equations showed that a single motor is needed to develop the wave motion, realizing this motion mechanically was not simple. I found the solution when I was teaching the course Mechanical design and realized that the side projection of a spring is a sine function that advances when the spring is rotated

How small could you ultimately make SAW? Is it possible to have a similar sized robot in the future that could be used to travel inside the human body?

The main purpose of the SAW robot is to crawl inside the body. Our latest design is less than 1.5 cm wide and it is capable of crawling inside the intestine of the pig (ex-vivo). Currently, we are seeking funding to develop smaller robots to crawl inside the digestive system. We believe this is very possible.

One of the observations that I made from your robots is that many of them are based on simplicity. Do you intentionally try to be minimalist when it comes to the number of working components in any robot?

We do follow the logic of simplicity. A saying attributed to Albert Einstein says ”Everything should be as simple as possible but no simpler”. A smaller number of components means better reliability, longer working life, higher power density and makes it much easier to reduce the size of the robots.

What are you currently working on?

In my Ben-Gurion University lab, we are currently working on multiple projects which include modeling of a robot which can crawl inside the body, serial robots for agricultural applications and some small search and rescue robots.

Anything else that you would like to share with our readers?

I strongly encourage parents and children to engage in mechatronics/robotics. With today’s technology, it is possible to buy user friendly components (3D printers, arduino controllers, motors, sensors, etc.) at low cost and program them with available home resources. It can be a fun activity for the whole family (especially in this period of time where we are mostly at home). I also encourage kids to engage in sciences and the usage of computers for educational purposes (not just gaming).

Thank you for the interview. I really enjoy learning about your unique approach to designing trully innovative robotics. Readers who wish to learn more should visit the Bioinspired and Medical Robotics Laboratory.