Demonstrates the optimization of the driving signal, which enhances the output performance of the thin piezoelectric print head while simultaneously reducing heat generation, ensuring thermal stability.
The experiment illustrates the difference in heat generation when creating the same displacement depending on the driving signal. (a) Thermal images corresponding to the driving period and the number of driven channels under bipolar signal application, (b) temperature graph based on driving period when four channels are operated, (c) temperature graph based on the number of channels when the driving period is 16μs. For unipolar signal application: (d) thermal images based on driving period and number of driven channels, (e) temperature graph based on driving period when four channels are operated, (f) temperature graph based on the number of channels when the driving period is 16μs.
(a) Time-lapse images of the dispensed liquid, (d) optical images of hydrogels printed on untreated substrate (left) and hydrophobic glass (right), (e) printing results with hydrogels at 1mm intervals, 3mm intervals, and 5mm intervals from left to right.
Newswise — Bioprinting is a technology used to create three-dimensional structures, such as human tissues or organs, using bio-inks made of cells and hydrogels. However, conventional inkjet technology has difficulty dispensing bio-inks that are sensitive to temperature due to the heat generated during operation. Furthermore, conventional 3D bioprinting mainly utilizes simple syringe-type printing devices with a single needle, making it time-consuming to produce artificial organs like the brain, lungs, and heart.
The Bionics Research Center team, led by Dr. Byung Chul Lee at the Korea Institute of Science and Technology (KIST, President Sang-Rok Oh), in collaboration with Dr. Seung-Hyup Baek’s team at the Electronic Materials Research Center and Professor Tae-Keun Kim’s team at Korea University (President Dong-Won Kim), has developed a bio-ink inkjet print head using the piezoelectric material PMN-PZT. This new print head is thinner but performs better than conventional designs. When applied, it enables the simultaneous dispensing of bio-ink at high resolution in multiple positions, significantly improving bioprinting productivity.
The research team developed a multi-nozzle inkjet print head using high-performance PMN-PZT thin films. This technology allows individual control of 16 ink ejection units arranged at 300 μm intervals, resulting in 16 times higher driving efficiency compared to than conventional methods. This enhancement boosts productivity and stability in bioprinting, reducing the production time for artificial organs.
In experiments, the team successfully printed hydrogels, a type of bio-ink, at a diameter of 32μm—half the size of conventional methods. The print speed achieved was 1.2 m/s, approximately 60 times faster than traditional methods. Additionally, the heat generation was reduced by 73.4%, keeping the temperature increase below 3.2 degrees Celsius during printing, ensuring a stable output environment. This allows for precise dispensing of high-viscosity materials and minimizes the deformation of temperature-sensitive bio-inks.
The PMN-PZT-based print head developed in this research can be utilized in organoid fields such as artificial organ transplants and drug toxicity evaluations, where thermal stability has been challenging. Furthermore, the operating temperature remains below 30 degrees Celsius, preventing the deformation of temperature-sensitive electronic materials and providing a stable printing environment. Therefore, it has the potential for broad application in various industries, including electronic components beyond the medical field.
Dr. Lee stated, “The new print head using PMN-PZT thin film material has enhanced the potential for high-resolution 3D organoid model production,” adding, “We plan to commercialize a 3D bioprinter capable of creating organs applicable for transplantation and toxicity evaluation by experimenting with various bio-inks such as gelatin.”
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KIST was established in 1966 as the first government-funded research institute in Korea. KIST now strives to solve national and social challenges and secure growth engines through leading and innovative research. For more information, please visit KIST’s website at https://eng.kist.re.kr/
This research was supported by the Ministry of Science and ICT (Minister Sang Im Yoo) through KIST's Major Projects and the National Core Materials Research Project (NRF-2020M3D1A2101933) funded by the Ministry of Science and ICT (Minister Sang-Im Yoo). The research findings were published in the international journal Sensors and Actuators B: Chemical (IF 8.0, JCR field 0.7%).
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Credit: Korea Institute of Science and Technology
Caption: Demonstrates the optimization of the driving signal, which enhances the output performance of the thin piezoelectric print head while simultaneously reducing heat generation, ensuring thermal stability.
Credit: Korea Institute of Science and Technology
Caption: The experiment illustrates the difference in heat generation when creating the same displacement depending on the driving signal. (a) Thermal images corresponding to the driving period and the number of driven channels under bipolar signal application, (b) temperature graph based on driving period when four channels are operated, (c) temperature graph based on the number of channels when the driving period is 16μs. For unipolar signal application: (d) thermal images based on driving period and number of driven channels, (e) temperature graph based on driving period when four channels are operated, (f) temperature graph based on the number of channels when the driving period is 16μs.
Credit: Korea Institute of Science and Technology
Caption: (a) Time-lapse images of the dispensed liquid, (d) optical images of hydrogels printed on untreated substrate (left) and hydrophobic glass (right), (e) printing results with hydrogels at 1mm intervals, 3mm intervals, and 5mm intervals from left to right.
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