Scalable manufacturing of thermoelectric nanomaterials has become a critical focus for enabling their widespread adoption in energy harvesting and cooling applications. Industrial-scale production methods must balance cost, throughput, and performance to meet commercial demands. Among the most promising techniques are roll-to-roll printing and aerosol jetting, which offer distinct advantages in terms of scalability while presenting unique trade-offs in material properties and process economics.

Roll-to-roll printing is a high-throughput manufacturing method adapted from the graphics industry for depositing thermoelectric nanomaterials onto flexible substrates. This process involves the continuous feeding of a substrate through multiple stations for material deposition, drying, and annealing. The primary advantage lies in its speed, with production rates exceeding several meters per minute, depending on ink formulation and drying requirements. For thermoelectric materials such as bismuth telluride (Bi2Te3) or lead telluride (PbTe), roll-to-roll compatible inks are formulated using nanoparticle dispersions or organometallic precursors. The cost per unit area can be as low as a few dollars per square meter when produced at scale, making it economically viable for large-area applications like wearable thermoelectric generators. However, the thermoelectric figure of merit (ZT) of printed films often lags behind bulk materials due to reduced crystallinity and increased interfacial resistance between nanoparticles. Typical ZT values for roll-to-printed thermoelectrics range between 0.4 and 0.8, compared to 1.0–1.5 for single-crystal counterparts. Post-processing steps such as thermal annealing or laser sintering can improve performance but add complexity and cost.

Aerosol jetting is another scalable method, particularly suited for precision patterning of thermoelectric nanomaterials. Unlike roll-to-roll, aerosol jetting operates in a non-contact manner, depositing nanoparticle-laden aerosols through a focused gas stream. This allows for high-resolution features (down to 10 µm) and compatibility with non-planar substrates, making it attractive for applications requiring intricate geometries, such as micro-coolers for electronics. Throughput is lower than roll-to-roll, typically in the range of centimeters per second, but the method offers better control over film morphology and density. Aerosol-jetted films of materials like silicon-germanium (SiGe) alloys have demonstrated ZT values approaching 0.9, with minimal post-processing. The trade-off comes in the form of higher equipment costs and more expensive ink formulations, which can increase the per-device cost by a factor of 2–3 compared to roll-to-roll.

Cost analysis for these methods must account for material waste, energy consumption, and capital expenditure. Roll-to-roll systems require significant upfront investment in machinery, often exceeding several million dollars, but the per-unit cost drops dramatically at high volumes. Aerosol jetting systems are less capital-intensive but have higher operational costs due to nozzle maintenance and aerosol generation. Material utilization efficiency also differs: roll-to-roll processes can achieve over 90% material usage with optimized doctor blade or slot-die coating, while aerosol jetting typically operates at 60–70% efficiency due to overspray and nozzle losses.

Throughput is a critical factor in determining the suitability of a manufacturing method for specific applications. Roll-to-roll printing excels in applications requiring large quantities of thermoelectric films, such as energy-harvesting fabrics or building-integrated thermoelectric panels. Aerosol jetting, while slower, is better suited for low-volume, high-value applications like medical devices or aerospace components where precision outweighs production speed.

Performance trade-offs extend beyond ZT values to mechanical durability and thermal cycling stability. Roll-to-roll printed films on polymer substrates often exhibit flexibility but may degrade under prolonged thermal stress due to polymer softening. Aerosol-jetted films, particularly those deposited on ceramic or metallic substrates, show better thermal stability but can be brittle. Advances in hybrid approaches, such as combining roll-to-roll deposition with selective laser annealing, are emerging to mitigate these limitations.

Environmental considerations also play a role in scalable manufacturing. Roll-to-roll processes often require solvents for ink formulation, raising concerns about volatile organic compound emissions. Water-based inks are under development but currently sacrifice nanoparticle stability and film quality. Aerosol jetting reduces solvent usage but may involve energy-intensive aerosol generation methods. Lifecycle assessments indicate that both methods can achieve a lower carbon footprint than traditional bulk thermoelectric manufacturing when optimized for material and energy efficiency.

Future directions in scalable manufacturing of thermoelectric nanomaterials include the integration of in-line quality control systems using optical or electrical monitoring to reduce defect rates. Machine learning-assisted process optimization is also being explored to dynamically adjust printing parameters for consistent film properties. As these technologies mature, the gap between lab-scale performance and industrially produced thermoelectric nanomaterials is expected to narrow, enabling broader adoption across energy and electronics sectors.

In summary, roll-to-roll printing and aerosol jetting represent two viable pathways for scalable thermoelectric nanomaterial production, each with distinct cost structures, throughput capabilities, and performance characteristics. The choice between them depends on the specific application requirements, balancing factors such as production volume, precision needs, and target ZT values. Continued advancements in process engineering and material formulation will be essential to further improve the economic and functional viability of these manufacturing methods.