Sometimes Dreams Do Get Printed

Emerging technologies of 3D printing in four dimensions, that include printing materials that change form when exposed to various triggers in the fourth dimension, are leading the fourth industrial revolution and opening possibilities for revolutionary applications in fields of medicine, construction, defense and others

While most of us are excited about the possibilities offered by 3D printing, Prof. Shlomo Magdassi, who until recently headed the Center for 3D Printing at the Hebrew University’s Institute of Chemistry, is already working in the fourth dimension – printed materials that can change shape, respond to their surroundings, and even perform complex tasks when exposed to a certain trigger e.g., to identify extreme situations of danger (toxic gas) by changing color or shape. In his lab at the Hebrew University, Prof. Magdassi is presently working on subjects of what he calls “the fourth industrial revolution” which, in his view, will change the face of industry, medicine, construction, and even the daily life of each and every one of us.

Welcome to the Era of Printing in Four Dimensions

“4D printing is the next generation of 3D printing”, Prof. Magdassi explains. “This is 3D printing with materials that change shape, and which can change when influenced by a fourth dimension such as light, temperature, air pressure, heat, drying or immersion in water, contact with acid or activation of a magnetic field, etc. The materials used are responsive, so when a coating created with one material is placed on a second material with a different thermal expansion coefficient, it may change via heating or electric pressure, thereby causing movement and a change of shape. Using precise structural planning, it is also possible to cause this element to perform a task – to lift or open something”, he explains.

“4D printing is an advanced technology that enables the creation of materials and structures capable of changing their shape or qualities in response to external stimuli such as heat, light, moisture, or magnetic fields. The Innovation Authority has chosen to invest resources in this technology because of its significant potential for applications in various fields. In the healthcare field, this technology can be used to create stents and to print personalized organs that respond to changes in the body and provide personalized medical solutions. In the field of construction, shape-morphing materials can be used to create shells for buildings that regulate the internal climate according to external environmental conditions, thereby enhancing energy efficiency. In the field of defense, it is possible to develop engineless robots that change according to need, thereby enabling greater flexibility in the battlefield. Furthermore, it will be possible to print products from innovative materials that can identify hazardous situations such as toxic gas, by changing color or shape, thereby providing early warning. The investment in this technology stems from its potential to change how we contend with challenges in different fields and to provide innovative and efficient solutions”.

Prof. Magdassi views these developments as part of a broader process. “After the machine, electric, and computer revolutions, we are now in the middle of the fourth industrial revolution that is creating a connection between the physical and digital worlds, between software and printer. The outcomes of this revolution are printed in four dimensions”.

The Chemistry Behind the Revolution

The applications of this technology have far-reaching implications and challenge the imagination. “For example, clothes that adjust themselves to cold or heat, medicines that are released in the body according to a certain trigger, or dynamic flowers from polymers that open when exposed to light and whose movement can be harnessed for different functional purposes”, Prof. Magdassi emphasizes. “This is a 3D component printed with meticulous design on a computer that can change shape according to a predetermined trigger.

The field of 4D printing is considered extremely promising. It is still not clear how this groundbreaking technology will enter the market, but the idea is to use printing methods and materials that will enable control and planning of the printed product’s final shape”.

For decades, Prof. Magdassi has been engaged in the chemistry of materials and their applications in different fields. In recent years, he and his research team have focused primarily on colloid chemistry and nanomaterials (between a millionth to a thousandth of a millimeter) for printing. The use of nanoparticles is intended to develop new processes, materials and structures that can be printed, coated, or colored in 2D, 3D, and even 4D printing, and create shape-morphing materials.

The technology is based on materials chemistry and on the choice of appropriate printing method. In practice, 3D printing involves printing layer upon layer, using selective laser fusion of dust particles or selective jet injection of color. In other words, the printing is done vertically”.

Prof. Magdassi explains however that “it is also possible to use a bathtub to print 3D bodies in water. In this way, the material transforms from liquid to solid via selective light radiation from underneath, for example only in places where the light falls. Some things cannot be done with regular printing and in a single casting, for example, a 3D model that is composed of, among others, two moving cogwheels. But they can be created via assembly or with sophisticated 3D printing where one of the materials disappears while the space it occupied remains”.

Applicable Technologies in a Variety of Fields

While university professors usually produce academic articles and publications, Prof. Magdassi – considered an extremely productive inventor – has also produced patents and technologies with practical market applications. Many of his studies have matured into products in Israeli and global industry and the creation of local and international companies.

The applications that he and his team develop are functional and include, among others, 2D and 3D coatings. For example, one of the materials developed, together with Prof. Danny Mandler, is a black paint that is durable at high temperatures and which is used to paint thermo-solar devices for producing solar energy.

Another fascinating project that Prof. Magdassi is working on is being applied in Singapore – “Smart Gripper” – a soft robot that integrates the 2D, 3D and 4D worlds. “This robot is made from extremely soft materials and can lift things. Because its touch was designed to be soft, it can lift an egg without breaking it because the robot has sensors that instruct it when to press more or less, and when to release”.

A further development in which Prof. Magdassi is involved is a sponge-like material that imparts durability to material incorporated into it during the manufacturing process, such as carbon nanotubes – a material that is resistant to fractures.

An extraordinary collaboration between Prof. Magdassi, Dr. Shay Duvdevani and Dr. Orit Steinberg and Tel Hashomer Hospital led them to engage jointly in the field of printing organs. The objective of the project is personalized printing for a specific patient, for example, the printing of 3D cartilage, facial reconstruction and more. The technology is still not fully mature but the tools being built today will enable this in the future.

Printing Polymers for the Space Industry

Among the materials developed in Prof. Magdassi’s laboratory are groups of polymers with a crystalline segments that are capable of returning to their original shape after fusion and spontaneous cooling. These polymers constituted the foundation for the creation of the incubator company “Noga Trade In”. The company engages in the printing of polymers for the space industry and is supported by the Innovation Authority. The use of this material, also called shape-memory polymers, enables to open an antenna in space or a capsule of drugs according to a certain trigger e.g., when encountering liquid. In other words, these are also shape-morphing materials.

Israel is considered a leading powerhouse in the field of printing, and Prof. Magdassi attributes a large part of this success to the Innovation Authority which supports research and development in this field.

“For me, the Innovation Authority is relevant on two levels”, Prof. Magdassi explains. “On the general-national level, these are extensive projects that enter the Applied Research in Academia (formerly “MAGNET”) Program with a certain theme, such as digital printing. The second level is the support for specific projects via programs such as the Consortiums program (formerly “KAMIN” and “NOFAR”) and others. Thanks to this support, it is possible to develop ideas that are difficult to work on commercially”.

The Next Industrial Revolution

This functional printing, of things that know how to “do something”, is not new. For example, printing of prototypes began already in the 1980s, when sports shoes were designed on a computer and printed in 3D. The significant change is the transition to industrial manufacturing, combined with personalization – i.e., products tailored for a specific individual. This is not a cheap process but it’s quick and personalized”.

The printing technologies enable the use of “ink” to print any material: ceramic, glass, crystalline and even wooden materials. “On the practical level we are working, for example, on the development of light ceramic materials such as a plastic that acts like ceramic materials in an oven”, Prof. Magdassi says. “The advantage is that when the chemistry of materials in a solution is mixed with the chemistry of materials in light radiation, we can create new transparent materials that can also be recycled. To create structures, we create new materials or give new life to existing materials via printing”. And that, naturally, opens a huge range of new solutions and application possibilities.

For example, as the result of a joint study by Prof. Magdassi and Prof. Eran Sharon from the Physics Institute, Prof. Oded Shoseyov from the Department of Agriculture, and the doctoral students Doron Kam and Ido Levine, an innovative method was developed for printing wood chips with bonding materials and water. The technology allows for advance design and programming of the chips during drying. Another article published by Prof. Magdassi and his colleagues described the capability of designing the material so that it will change shape while drying according to predefined conditions.

Anything Can Be Printed

When looking forward, the possibilities seem endless. “Anything can be printed”, says Prof. Magdassi enthusiastically. “We can print conductive material or material which is sensitive to light and can monitor the amount of surrounding light, or material that diffuses light and constitutes a substitute for light bulbs, or a smart window that contains conductive material and which transforms from opaque to transparent at the touch of a button. We combine data and “purpose”. All you need, is to think about what you want to create, to turn it into a computer file, and to choose the right materials”.

The fourth revolution is already here. Printed, smart, flexible and personalized, and it will change our lives in ways that are still difficult to conceive. From clothes that adjust themselves to weather conditions, medicines that are released in the body at precisely the right moment, to soft robots that can perform delicate tasks – four-dimensional printing is opening a range of new possibilities.