The United States Patent and Trademark Office (USPTO) has published a new patent from New York-based IT multinational International Business Machines Corporation (IBM). Originally filed in August 2023, the document (US Patent No. 20250073998) outlines a novel method for transporting microparticles using 4D printed smart materials.
According to IBM’s filing, these 4D printed substances move in response to external stimuli like heat, light, magnetic fields, or electricity. Therefore, they can be configured and manipulated to deliver microparticles (1-100µm in diameter) from a starting point to a target location in small, hard-to-reach areas.
The US tech giant’s method uses a computer program to monitor the movement of the smart materials. If the 4D objects deviate from their intended path, machine learning models adjust the inputs to keep the microparticles on track. IBM highlights drug delivery, cell microcarriers, miniature electronics assembly, and micro-manufacturing as potential applications.
IBM’s AI Engineer Tushar Agrawal and Application Architect Sarbajit K. Rakshit, who helped invent the new 4D printing-enabled method, bring significant additive manufacturing pedigree. Agrawal has contributed to over 180 patent applications, including a proposal to 3D print objects from decomposable materials and monitor their breakdown over time. Rakshit, who possesses nearly two decades of IBM experience, was behind the company’s hologram 3D printing patent filed in 2017.
Former IBM software developer Vinod A. Valecha is also named on the patent. Now working at San Jose tech firm Cohesity, he previously contributed to IBM’s patent for continuous 3D printing with a collapsable build plate. Valecha also co-invented a “parallelized additive manufacturing” process that fabricates a deconstructed part simultaneously on multiple 3D printers. Su Liu, a “Master Inventor” at IBM, is also named on the newly published 4D printing patent.
IBM’s new 4D printing patent
IBM’s 4D printing process begins when the computer program receives a user request to transport microparticles from a starting position to a target location along a specific path. Each request includes key characteristics like microparticle size, shape, weight, and material composition. The delivery path and environmental conditions must also be specified, with the small-scale smart printed material able to move through mediums spanning industrial environments, intestinal tracts, and arteries.
IBM’s program analyzes the request and uses ML models to design a 4D printable object optimized for microparticle delivery. Smart materials that can be used in these objects include shape-memory alloys and shape-memory polymers. Both can return to their original shape after being heated or deformed.
If the microparticles are small enough, they can be directly attached to the surface of the movable 4D object. However, for larger and heavier microstructures, IBM suggests rigid, 3D printed containers. These fasten to the smart materials and hold the microplastics during transportation.
Once triggered, IBM’s program applies an external stimulus to activate the 4D object. The smart material responds by deforming and generating forces that enable movement. For example, heat causes shape-memory materials to bend or fold, while light triggers movement in photo-responsive materials. Magnetic fields can also be used to either attract or repel the 4D object, guiding its movement in a specific direction.
IBM’s patented process uses ML models to continuously monitor the 4D printed object as it moves along the delivery path. If any deviations or blockages are detected, the algorithm instantaneously analyzes the issue and adjusts the stimuli to correct its movement. Once it reaches the target location, IBM’s program removes the external input, stopping movement and delivering the microparticles.
According to the Silicon Valley tech leader, its newly published patent offers significant potential for several high-value applications. For instance, it could provide a precise method for targeted drug delivery by transporting medicine throughout the body to specific organs or tissues. Within the electronics sector, IBM’s novel process could be used to assemble miniature electronic components with extreme precision. The smart materials can also move microparticles in small spaces where conventional manufacturing machines and robots can’t reach, offering value for microfabrication.
4D printing: a new dimension for additive manufacturing
4D printing is by no means a new concept. Back in 2021, Researchers from China’s Tianjin University developed a 4D printed soft robot capable of movement.
The tube-shape device was made of liquid crystal elastomer, which allowed it to self-assemble when subjected to heat. It was designed to leverage fold patterns to create strain within its structure, allowing it to roll and traverse flat surfaces. The 4D printed robot also demonstrated the ability to climb a 20° incline and drag a load up to 40 times its own weight.
A team of German, Egyptian, and UAE-based researchers also developed a novel method to create 4D printed dental aligners with memory capabilities. DLP-printed from Kline Europe’s transparent ClearX resin, the orthodontic device is designed to soften once inserted into a user’s mouth. This allows the aligner to adapt to, grip, and reposition misaligned teeth. The researchers demonstrated an ability to predictably change the aligners’ properties over time, making it a sustainable alternative to single-use dental products.
Elsewhere, a team from Queen’s University Belfast developed personalized 4D printed breast implants to manage and treat cancer. According to the researchers, this was the first time 4D printing was used to produce breast cancer implants.
Using this process, the Northern Ireland-based scientists fabricated multipurpose breast implants that can be programmed to change size to better fit into the patient’s tissue cavity. This reportedly unlocks greater personalization and improved aesthetic outcomes. The 4D printed implants can also be programmed to release chemotherapy drugs where they are needed, protecting against the return of cancer cells.
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Featured image shows the IBM logo. Photo via IBM.
