Article first published in the June 2019 issue of 3D ADEPT MAG, then online in August 2021. Quotations and examples retain their historical context; the clarifications below correct generalisations about security and technology maturity.
Blockchain was being studied for additive manufacturing before 2018, including in Deloitte’s 2016 report. This 2019 feature examines its potential for traceability and data sharing between manufacturing participants.
A blockchain organises a shared ledger into cryptographically linked blocks. It may be permissionless or permissioned. Governance and data visibility depend on the architecture; not every blockchain is public or lacks authority.
In AM, the proposed value is tracing exchanges, rights and data versions. A ledger replaces neither design-file storage nor the checks needed to qualify a part.
What’s that digital thread?
According to an analysis of Deloitte on “3D Printing opportunities for blockchain”, “for AM processes to scale at the industrial level, a series of complex, connected, and data-driven events likely needs to occur. In this way, successfully deploying AM is less a physical- or hardware-associated production challenge and more a data- or records-management one. This is referred to as the digital thread for additive manufacturing (DTAM)”.
The digital thread links a part’s design, manufacturing, validation and service information. This data continuity can be organised without a blockchain.
Scaling requires usable data, interoperable systems and clearly assigned responsibilities.
When does blockchain come into play?
One essential use of AM among 3D printing service bureaus suggests to implement a distributed model across a number of partners around the world. This AM supply chain is only possible thanks to the transmission of data and interconnectivity.
The digital thread can connect topology optimisation and multiphysics simulation results to manufacturing stages. These tools are not intrinsic blockchain functions.
“In the same way that the DTAM supports both supply chain scale and product innovation, the blockchain for AM has the potential to serve as a backbone and security layer for the DTAM, underpinning all of the transactions that occur throughout the digital and physical life cycle for AM”, explained analysts from Deloitte. It really looks like a chain of trust between stakeholders.
The chain of trust and its advantages
A group of scientists that published the study, “Intellectual Property Protection and Licensing of 3D Print with Blockchain Technology,” explained that a license can be issued to specific users to print a certain number of parts. Speaking of “Chain of Trust” between several parties including trusted printers, copyright holders and service providers, they explained that such type of process is built from the development of digital 3D data to the labeling of 3D printed components with RFID chips.
The 2018 study by Engelmann and coauthors presents a licensing architecture. The link between digital identity, printer and physical object itself needs securing.
Sharing a ledger may assist checks between partners, depending on access rights. It does not automatically make every entry reliable or visible to everyone.
The GE example concerns patent application US20180173203A1, published on 21 June 2018, describing a distributed manufacturing history. A patent application does not establish widespread industrial deployment. The following passages set out its authors’ problem statement and proposed solution:
When a third-party reproduces a replacement part for an industrial player, end users cannot verify whether the replacement part “was produced using a correct build file, using correct manufacturing media, and on a properly configured additive manufacturing device.”
For GE, “It would therefore be desirable to provide systems and methods for implementing a historical data record of an additive manufacturing process with verification and validation capabilities that may be integrated into additive manufacturing devices.”
However, this concept of trust between parties is controversial. While researchers talk about building trust between stakeholders, the audit firm Deloitte explains that trust still needs to be strengthened. For the auditing firm, the blockchain technology does not eliminate the need for trust between parties. “It replaces the existing mechanism for gaining trust (bank, escrow, and so on) with cryptography, and maintaining that trust is not cost-free. The method via which trust is achieved is called the consensus mechanism, and the cost is referred to as the incentive structure—how the maintenance of trust is sustained. These are the two fundamental pillars of blockchain, referred to as the consensus mechanism, and an incentive structure to sustain the expenditure of effort for that validation to take place and continue. The exact features of those two elements are tailorable across different ecosystems, but the success of the protocol often depends on those two foundations.”
Security: distinguishing traceability, confidentiality and quality
NIST (2018) explains blockchain limitations. Ledger integrity ensures neither file confidentiality nor the accuracy of initial entries. Encryption does not eliminate hacking risks; keys, accounts and equipment also need protection.
Resistance to modification depends on protocol and governance. It is not an absolute guarantee and does not validate a part’s physical properties.
Speed: examining the complete workflow
Automating authorisations or exchanges may reduce administrative tasks. It does not make manufacturing almost instantaneous: file preparation, machine compatibility, validation and physical production remain necessary. The consensus mechanism may also add delay.
A printer network can operate without blockchain. A distributed ledger should address a specific need between partners and be compared with a conventional shared database.
Approaches investigated in the late 2010s
The examples in this feature include a prospective analysis, a research architecture and a patent application. They illustrate integration approaches without measuring adoption across the AM industry.
The original figure of five companies out of twenty was not tied to an identifiable survey or method. It has therefore been removed from this analysis; it could not establish an adoption rate.
The useful question is which coordination problem blockchain would solve, who would govern the network and how data would be verified. The decision depends on costs, confidentiality, interoperability and partner requirements rather than technology availability alone.
This exclusive feature has first been published in the 2019 June issue of 3D ADEPT Mag.
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