4D 프린팅:3D 프린팅의 미래

파이프가 자동으로 스스로 고칠 수 있다면 어떨까요? 금이 가거나 부러지거나 옷이 날씨나 사용자가 하는 활동에 따라 변경될 수 있는 경우 ? 스스로 조립하는 가구, 성장에 적응하는 보철물... 이것들은 4D 프린팅 기술이 실현할 것으로 예상되는 응용 분야 중 일부에 불과합니다.

이미지 1:모양을 수정하는 4D 프린팅 발톱. 출처:Sculpteo.

3D 프린팅 거의 30년 동안 존재해 왔으며 여전히 연구 과정에 있는 동안 새로운 재료 및 응용 프로그램, 4D와 같은 새로운 기술이 등장했습니다.

MIT 자가 조립 연구소에서 , 그들은 4D 인쇄가 일부인 프로젝트를 개발했습니다. 그 목적은 기술과 디자인을 결합하여 프로그래밍 가능한 재료를 발명하는 것입니다. 건설, 제조, 제품 조립 및 성능을 재창조하기 위한 자체 조립 기술. 한편, Wyss Institute의 연구 (하버드 대학의 일부) 물과 접촉하면 모양이 변하는 물체를 인쇄하는 데 성공 e, 그 결과 일종의 꽃이 피었습니다. 그들은 인쇄 과정에서 셀룰로오스 섬유를 주입하여 식물과 같은 자연 구조를 기반으로 하는 소재를 개발했습니다.

동영상 1:형태를 바꾸는 건축. 출처:하버드 대학교.

4D 프린팅이란?

자가 조립 원리에서 영감을 받은 4D 프린팅은 3D 프린팅된 물체가 온도, 빛 또는 기타 환경 자극과 같은 외부 에너지 입력의 영향에 의해 다른 구조로 변형되는 과정입니다. 즉, 3D 기술을 통해 물체를 얻는 것입니다. 물체를 만드는 재료의 특성 덕분에 환경적 자극을 받으면 변할 수 있습니다.

이것이 바로 차이점입니다. 3D와 4D 기술 사이:사람의 개입 없이 시간이 지남에 따라 물체가 변형되는 능력

사용된 재료

4D 프린팅의 핵심은 과정이 아닙니다 , 친숙한 3D 프린터를 기반으로 하지만 재료 이것은 상당히 새로운 기술이기 때문에 사용 가능한 재료는 표준 3D 프린팅에 사용되는 재료만큼 다양하지 않습니다. 그러나 매우 흥미로운 것들이 있습니다.

SMP(형상기억폴리머)

상온에서 단단한 상태를 유지하고 유리 전이점에 도달하면 특별한 특성을 제공하는 폴리머. 예를 들어 Convena의 TPU SMP:TPU 기반 구성의 4D 필라멘트 (열가소성 폴리우레탄) 후처리를 통해 3D 프린팅 부품의 모양을 수정할 수 있습니다. Thanks to its special composition and Shape Memory Polymer technology, parts printed with this filament can be modified manually, allowing them to acquire another shape and maintain it over time.

The process of modifying the shape of a 3D printed part with SMP TPU filament consists of placing the 3D printed part in a container of hot water until it reaches its glass transition temperature. At this point, the part softens and the user can easily modify its shape. Once cooled, the part maintains the acquired shape and remains stable. In addition, parts 3D printed with SMP TPU filament can be restored to their original shape by reversing the process. In other words, the material's glass transition temperature is reached again.

LCE (liquid crystal elastomers)

They contain liquid crystals that are sensitive to heat. By controlling their orientation, the desired shape can be programmed: under the effect of temperature, the material will relax and transform according to the dictated code.

Hydrogels

Polymer chains consisting mainly of water , particularly used in light-curing processes. The latter are focused on the medical sector due to their biocompatibility.

In addition, some 4D printing processes can use various materials, mainly composites such as wood or carbon, which are added to SMP or hydrogels. This results in objects with rigid and movable areas.

Applications

Given the many advantages of such intelligent materials, the applications of 4D printing are innumerable.

Construction

The construction of climate-adapted structures such as bridges, shelters or other facilities would be a huge step forward in this field. 4D bricks capable of modifying walls and roofs to suit the environment would allow indoor conditions to be modified and improved.

Video 2:Programmable wood. Source:Self-Assembly Lab, MIT.

Medicine

In this case, 4D printing offers the possibility to create tailor-made, intelligent and evolving devices. For example, by 4D printing an implant, its condition and viability could be more easily monitored once it is integrated into the patient.

This concept is applicable to all regenerative medicine and the fabrication of cellular structures. 4D printing would allow cells to adapt to the human body depending on its temperature, for example. If we talk about medicines, it would be possible, for example, to print a device that would release the required dose depending on the patient's body temperature.

Transport

A few months ago, BMW and MIT presented their inflatable material, which changes shape and size under the effect of air pulses. The applications are very interesting, as in the future we could have tyres that can repair themselves in case of a puncture or adapt to the terrain and weather conditions of the environment.

In the case of the aircraft industry, a 4D printed component could react to atmospheric pressure or temperature changes and thus change its function. Airbus is currently working on such developments, as these components could replace hinges and hydraulic actuators, significantly lightening the devices . In addition, it is also working on the development of heat-reactive materials to cool its aircraft engines.

Raúl Pulido Casillas, a Spanish engineer, has created a 4D-printed smart fabric for NASA. The metallic mesh, made of silver pieces joined together, has thermal regulation programmed into its print. In other words, not only its shape has been printed, but also the function of the materials. As it is able to reflect heat on the outside and retain it on the inside, it could be an ideal element for making astronaut suits or covering spacecraft.

Fashion

In the textile industry, 4D printing is also finding its place. The possibility of printing shoes that adapt to movement, impact, temperature and atmospheric pressure is a possibility. The US military has already made a foray into this field and is testing uniforms that change colour depending on the environment, or that regulate perspiration depending on the soldier's pulse or the ambient temperature.

Although we are still in its infancy, it is certain that 4D technology will revolutionise the manufacture and nature of objects over the next few years, just as 3D printing did in its day.