Researchers at Nanyang Technological University, Singapore (NTU Singapore) have 3D-printed a ready-to-fly drone with embedded electronics using aerospace-grade material.

The drone – a quadcopter with four rotors – was designed, 3D-printed and flown by Phillip Keane, an NTU PhD candidate from the School of Mechanical and Aerospace Engineering who is engaged in research at NTU’s Singapore Centre for 3D Printing (SC3DP). The drone was jointly developed by the SC3DP and Stratasys Asia Pacific.

The electronics were incorporated in the drone during the 3D printing process, which employed the fused deposition modelling (FDM) process using Stratasys ULTEM 9085 – a high-strength, lightweight material certified for use in commercial aircrafts. In 3D printing, objects are created digitally layer by layer until completion. However, embedding electronics can be a challenge, as most will not survive the high temperatures of the 3D printing process.

Commercial-grade electronics were therefore modified and placed within the drone at the various stages of the printing process. They survived the high-temperature printing, which reached over 160 deg.C, compared to the usual 80 to 100 deg. Only the motors and the propellers were mounted after the entire chassis was completed.

“One of the toughest challenges was to find electronic components that could theoretically survive the high temperature printing process,” says Keane. “We had to add some heat-proofing modifications to the components to ensure they could last. This involved adding new components to the printed circuit boards and also designing custom housings.”

The drone was completed in under 14 hours. During the printing, there were just three pauses for the electronics to be placed within the chassis.

“The housings, which were pre-printed in ULTEM 9085, also provide a flat surface for the 3D printer to continue printing over them,” added Keane. “I also had to deal with tight time constraints as some of the components could not survive in the heat for more than 20 minutes.”

In addition to being extremely rugged, the drone is capable of supporting over 60kg of weight suspended from its structure. Moving forward, Keane says that he is currently working on the next version of the drone, which will feature better durability, lighter weight and improved flight dynamics.

Professor Chua Chee Kai, Executive Director of NTU’s SC3DP, said that this is a successful example of disruptive innovation that can be achieved when researchers from academia work with industry partners. Professor Chua himself is the world’s most cited scientist in the field of 3D printing according to the Web of Science, a research database maintained by Thomson Reuters

“At NTU, we have world-leading researchers with vast knowledge of materials and 3D printing processes, who have invented innovative techniques to overcome the limitations of existing technologies,” explained Prof Chua. “Together with Stratasys’ engineers and their intimate knowledge of 3D printing, we were able to push the limits of today’s technology and print a drone that is incredibly durable and can withstand high heat.”

“This project exemplifies the power of Stratasys’ flagship FDM 3D printing technology and perfectly demonstrates the strength of the ULTEM resin,” commented Fred Fischer, Director – Applications and Products, Stratasys Asia Pacific. “We look forward to researching, developing and unveiling more possibilities with 3D printing and materials as we work with industry partners and academia.”

ULTEM 9085 is a production-grade thermoplastic that can be 3D printed and is prized for its high strength-to-weight ratio and its FST (flame, smoke and toxicity) rating, making it ideal for the commercial transportation industry, especially aerospace.

Professor Louis Phee, Chair of the School of Mechanical and Aerospace Engineering at NTU, said that unmanned aerial vehicles (UAVs) are a major research thrust at the school : “Being the first university in Singapore to offer an Aerospace Engineering degree programme, we have been successful in attracting the brightest students to work with our professors to push the frontiers of drone technologies to cater to Singapore’s unique needs and requirements. In the near future, I expect to see more exciting new drone technologies from NTU that will be translated into real applications.”