Majidi receives award to continue work on ‘soft robotics’

Assistant professor of mechanical engineering Carmel Majidi recently won an award from the Air Force Office of Scientific Research (AFOSR) Young Investigator Program. The award comes with a $360,000 grant that will be used in part to fund a Ph.D. student working for Majidi in the field of soft robotics.

Soft robotics is a new domain in robotics where the robots are made of soft materials, as opposed to the types of rigid materials that conventional robots are made out of. These soft materials include elastomers, which are soft rubbers that are elastic and very stretchable. They can also be composed of fluids or gels.

One of the motivations behind soft robotics is to make robots and machines that are more life-like than curren robots. “The idea is that if robots and machines are made out of soft materials, then they will exhibit more of the functionality and properties that natural organisms have,” Majidi said.

According to Majidi, “The award addresses a very important challenge within the broader field of soft robotics.” Many of these challenges stem from the two necessities in soft robotics: electric power and materials to help power these biologically inspired robots. In addition, there is a need for materials that are able to harvest energy from their environment. The purpose of the Air Force award is to produce new classes of elastomers that can convert elastic deformation into electricity. When the soft robots move in an environment, they undergo large elastic deformations and collide with the surrounding surfaces. Thus they are going to absorb a lot of elastic energy that would otherwise be wasted. These robots contain special types of materials and transducers, and they can convert that elastic energy into electrostatic energy. This energy can be used to power different electronics inside the robot.

Majidi’s lab focuses on creating the materials that comprise soft robots.

One type of material that Majidi researches is an electronic artificial skin that would go on the outside of the robots. Inside the skin are sensing elements that can detect surface forces: surface friction, slip events, impact, collision, and contact pressures. The electronic skin can act as a stretchable type of electronic circuit that can go around the robot and support some of its electrically powered elements.

There are many potential application domains for the soft robots, such as the area of actuators (artificial muscles). Some of the technologies that Majidi wants to produce in terms of energy harvesting could potentially be used to help power artificial muscles and soft robot actuators. This energy harvesting could also be used for producing electricity to power the on-board sensors, electronic switches, and different circuit elements in the soft robot.

“The field of soft robotics is relatively new, but some of the underlying principles have been around for decades,” Majidi said. One paradigm in soft robotics is inflatable soft robots — these are elastomers that are inflated with compressed air, similar to balloons. According to Majidi, there has been decades of effort put toward artificial muscles based on this principle of pneumatic inflation, which uses pressurized gas to inflate devices. The novelty is that there have been a lot of advancements in rapid prototyping and in the fabrication and advanced manufacturing techniques. Now researchers can take the existing principles and apply them to create much more elaborate types of soft robots at different length scales.

“Another area that I’m involved with is soft matter electronics,” Majidi said. “These are not necessarily robots, but they could function as a robot skin.” They could also function as wearable electronics, devices that can be put on human skin. These are thin sheets of soft rubber embedded with microfluidic channels of different types of fluidic matters. A lot of the current work in Majidi’s lab is focused on that approach to stretchable electronics. “That also motivates a lot of the work in this Air Force award — which is to create electrostatic generators to help power the soft matter electronics and sensors,” Majidi said.

“I’m very grateful for the award and I’m very excited by this research,” Majidi concluded. “It’s great for the group and for the Carnegie Mellon community because it creates this opportunity to do cutting-edge research.”