3D Printing Bioelectronics: A Guide

IoT, smart devices, embedded electronics, wearables are just some of the latest trending keywords on social media, responding to a newer generation of consumers’ demand for both mass customization (i.e. affordable) and personalization (typically more expensive). Several market analyses reported that the global 3D printed electronics market is expected to have a CAGR of as much as 40% during the period of 2021-2028. Now living with the pandemic supply chain crisis that trend does not seem to slow down anytime soon. A decentralized manufacturing process that heavily utilizes digital processes is the intuitive logical step. A quick search in Pubmed demonstrates that research publications related to “3d printed bioelectronics” correspond to this market demand. [Figure 1] In this guide, we aim to outline the major enabling technologies, current applications, research activities, and groups, as well as entrepreneurial activities focusing on 3D printing bioelectronics. Some of this content is based on our mini-conference titled “3D Printed Bioelectronics”. While most of the work and commercial activities still surround research and development, we firmly believe the field of bioelectronics will be a significant disruptive force in future healthcare. That said, it is also wise to remember that it is still unknown how important a role 3D printing will play in the field. (Feature Image Photo Credit : Prof Shweta Agarwala, PET Lab (ECE, Aarhus University, Denmark)  )

bioelectronics publication
Figure 1. Number of publications with keywords “3D Printing + Bioelectronics” by Year

Outline of this Guide*: 

What is bioelectronics? 

What are some of the major applications of bioelectronics? 

How were electronics made in the past? 

Why do we need to 3D print bioelectronics? 

What are some of the challenges in 3D printing bioelectronics?

What are the latest advancements in 3D printed bioelectronics? 

What is bioelectronics? 

In professor Agarwala’s words, “bioelectronics is the marriage of biology and electronics”. The ideal bioelectronics needs to meet many demands including flexibility, shape requirements, biomechanics, biodegradability, and bio-absorbability, depending on the applications.  

What are some of the major applications of bioelectronics?

In the minds of scientists and technologists heavily invested in the field, bioelectronics can be everywhere in the human body or interfacing between the human body and his/her environment. 

These include but are not limited to textile, wearable devices, implants, biosensors (e.g. pressure, PH, strain), antenna (as part of an implant), transistor, among others. Outside of the human body, bioelectronics also play important role in diagnostics and biotechnological advancements.

How were electronics made in the past? 

In the past, a central component of electronics, the electronic circuit board, has been manufactured using various printing techniques. Hence, the concept “printed circuit board”, or PCB. So using 3D printing to design or manufacture the next generation of the circuit board is not too far stretched. Other previous 2D electronics printing processes include screen printing, flexography, gravure, offset lithography, inkjet, among others. The resulting products are typically rigid.

Why do we need to 3D print bioelectronics? 

Some of the biggest selling points of 3D printing as the alternative manufacturing process include mass customization, complexity for “free”, point of care manufacturing, thereby achieving a decentralized personalized healthcare delivery at theoretical equal or lower cost, with more accessibility and intelligence. 

New 3D printable ink and substrates allow for the next generations of bioelectronics, replacing typically rigid, intrusive, and permanent electronics in the market. For example, bioelectronics can be “printed” onto curved surfaces, or embedded into textile. 

In professor Agarwala’s recent presentation to the 3DEHALS audience, she presented a case involving 3D printed bioelectronics embedded in the stocking that prevents muscular atrophy from long-term bedridden COVID patients. Her other ongoing projects also include biodegradable implant antennas where information related to post-implantation outcomes can be immediately transmitted to the clinicians for better management. 

Beyond wearables and implants, the Wyss Institute also has demonstrated huge potentials of 3D printed electronics in diagnostics, for example, 3D printed organ-on-a-chip with integrated sensors. Perhaps someone else can make Theranos’ false promise into reality soon? 

While this is still in its infancy, 3D Printing also allows for the design of the next generation of PCB, where older PCB design concepts can now be replaced by three-dimensional, more complex designs that did not exist previously. Nano Dimension, an Israeli company focusing on manufacturing 3D printed electronics, in particular stacked integrated circuits (stacked ICs).

Finally, the additive manufacturing process (i.e. 3D printing) is theoretically more sustainable than traditional manufacturing processes because of less waste generated as a result.

What are some of the challenges in 3D printing bioelectronics?

  1. Technical Challenges

While all 3D printed bioelectronics is still in the research and development stage, it is also evident based on a quick Pubmed search that publications surrounding this subject are consistently trending up [Figure 1]. This trend will often manifest later in commercialization, so it should not surprise anyone that there will be more startups in the space. 

Another important challenge to address is finding the best power source for bioelectronics. Major potential power sources include traditional or new battery technologies, wireless power delivery (e.g. inductive coupling, radiofrequency, mid-field, ultrasound, magnetoelectrics, and light), and kinetic powered bioelectronics. For example, Piezoskin, a startup based in Lecce and a spin-off from the Center of Biomolecular Nanotechnologies of Instituto Italiano di Tecnologia (IIT), is developing a new fabrication protocol for soft piezoelectric transducers, which can harvest energy from body movements. 

  1. Economic Challenges

While everyone who works in the 3D printing industry dreams of completely replacing the trillion-dollar mass production systems, that is far from reality. Similar to the rest of the 3D printing industry, 3D printed electronics also face significant economic challenges due to the limitations of existing machines, methods, and materials. The “magic intersection” of production volume and price still limits current commercial players to limit applications on batch production items and not mass production. Most are also still at the prototyping stage, limiting the market size of commercialize 3D printable electronics. 

  1. Regulatory Challenges

Finally, given all the uncertainties related to current technologies and a lack of precedents, there will likely be a prolonged waiting period before a truly 3D printed bioelectronics to be on or inside of a patient. These uncertainties include standardization of new manufacturing processes, new materials, quality control processes, testing, and more. That said, many believe the end market is ambitious enough to justify the current risk of investing in this industry. 

“No risk no return” is the mantra. 

What are the latest advancements in 3D printed bioelectornics? 

While this guide does not intend to go in-depth of ongoing research, we believe the following concepts are worth further exploring for readers’ future independent research: 

  • Electronic Conducting Hydrogel – This is a great review article written by professor Shweta Agarwala. The article lists the latest conducting hydrogel as well as how 3D printing can be used to incorporate these new materials into new devices. 3D printing processes include 3D bioplotting, inkjet, and light-based printing.
  • Electronic Conducting Polymers – This is a great article “Conducting polymers are promising material candidates in diverse applications including energy storage, flexible electronics, and bioelectronics. This article discusses a high-performance 3D printable conducting polymer ink based on poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) for 3D printing of conducting polymers.  The resultant superior printability enables facile fabrication of conducting polymers into high resolution and high aspect ratio microstructures, which can be integrated with other materials such as insulating elastomers via multi-material 3D printing. The 3D-printed conducting polymers can also be converted into highly conductive and soft hydrogel microstructures. We further demonstrate fast and streamlined fabrications of various conducting polymer devices, such as a soft neural probe capable of in vivo single-unit recording.”

  • LIFT (Laser-Induced Forward Transfer) printing process – “Laser-induced forward transfer (LIFT) is a direct-writing technique based on the action of a laser to print a small fraction of material from a thin donor layer onto a receiving substrate. LIFT is a nozzle-free printing technique that has almost no restrictions in the particle size and the viscosity of the ink to be printed. Thus, LIFT is a versatile technique capable of printing any functional material with which an ink can be formulated.” This new printing process could play an important role in printing future bioelectronics. Interestingly, this same technique has also been commercialized by tissue engineering startups (Poeitis and Precise-Bio) to create 3D human tissue models.

Which major research groups are working on 3D printed bioelectronics? 

Printed Electronics Technology Group at Aarhus University, Denmark led by professor Shweta Agarwala

Holts Centre (powered by imec and TNO) – Hybrid Printed Electronics

Center of Biomolecular Nanotechnologies (CBN) of the Istituto Italiano di Tecnologia (IIT)

References: 

  1. https://en.wikipedia.org/wiki/Printed_circuit_board
  2. Electrically Conducting Hydrogels for Health care: Concept, Fabrication Methods, and Applications

*A 3DHEALS Guide is updated regularly based on 3DHEALS internal research and is free to 3DHEALS premium members

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