Researchers design origami-inspired, chip-free robots

Roboticists have been using a technique similar to origami to develop autonomous machines out of thin, flexible sheets. These lightweight robots are reportedly simpler and cheaper to make and more compact for easier storage and transport. However, the rigid computer chips traditionally needed to enable advanced robot capabilities – sensing, analysing and responding to the environment – add extra weight to the thin sheet materials and make them harder to fold. The semiconductor-based components therefore have to be added after a robot has taken its final shape.

A multidisciplinary team led by researchers at the UCLA Samueli School of Engineering has created a new fabrication technique for fully foldable robots that can perform a variety of tasks without relying on semiconductors. The research findings were published in Nature Communications.

By embedding flexible and electrically conductive materials into a pre-cut, thin polyester film sheet, the researchers created a system of information-processing units, or transistors, which can be integrated with sensors and actuators. They then programmed the sheet with simple computer analogical functions that emulate those of semiconductors. Once cut, folded and assembled, the sheet transformed into an autonomous robot that can sense, analyse and act in response to its environment with precision. The researchers named the robots ‘OrigaMechs’, short for Origami MechanoBots. Lead author Wenzhong Yan, a UCLA mechanical engineering doctoral student, said this work leads to “a new class” of origami robots with expanded capabilities and levels of autonomy while maintaining the favourable attributes associated with origami folding-based fabrication.

OrigaMechs derive their computing capabilities from a combination of mechanical origami multiplexed switches created by the folds and programmed Boolean logic commands, such as “AND”, “OR” and “NOT”. The switches enabled a mechanism that selectively output electrical signals based on the variable pressure and heat input into the system. Using this approach, the team built three robots to demonstrate the system’s potential. These included an insect-like walking robot that reverses direction when either of its antennae sense an obstacle; a Venus flytrap-like robot that envelops a “prey” when both of its jaw sensors detect an object; and a reprogrammable two-wheeled robot that can move along pre-designed paths of different geometric patterns.

Although the robots were tethered to a power source for the demonstration, the researchers’ long-term goal is to outfit the autonomous origami robots with an embedded energy storage system powered by thin-film lithium batteries. The chip-free design may lead to robots capable of working in extreme environments — strong radiative or magnetic fields, and places with intense radio frequency signals or high electrostatic discharges — where traditional semiconductor-based electronics could fail to function.

Study principal investigator Ankur Mehta, an assistant professor of electrical and computer engineering and director of UCLA’s Laboratory for Embedded Machines and Ubiquitous Robots, said origami robots could be useful during dangerous or unpredictable scenarios, such as during natural or manmade disasters. “The robots could be designed for specialty functions and manufactured on demand very quickly. Also, while it’s a very long way away, there could be environments on other planets where explorer robots that are impervious to those scenarios would be very desirable,” Mehta said.

Pre-assembled robots built by this flexible cut-and-fold technique could be transported in flat packaging for space saving; this is important in scenarios such as space missions, where every cubic centimetre counts. The lightweight and simple-to-fabricate robots could also lead to innovative educational tools or new types of toys and games. The research was supported by the National Science Foundation. Yan and Mehta are applying for a patent through the UCLA Technology Development Group.

Image caption: An origami-inspired robot designed by a UCLA-led team that can reverse direction when either of its antennae senses an obstacle. Image credit: Wenzhong Yan/UCLA.