Shape-Versatile 3D Thermoelectric Generators by Additive Manufacturing

Abstract

Additive manufacturing (AM) is a recent growing technology, which is currently implemented for different application fields, from rapid prototyping to cost-effective manufacturing of industrial components with complex shapes. Printable thermoelectric materials offer synergies with AM and can be integrated into 3D printed thermoelectric generators (TEGs). In this work, we have formulated an Ag 2 Se-based n-type printable thermoelectric (TE) ink with a high figure-of-merit of ∼1 at room temperature. Three scaffolds with different shapes have been printed using 3D printing. The developed ink as ntype legs and commercially available PEDOT as p-type legs were then painted on the 3D printed scaffolds to fabricate three TEGs with a different number of legs and shapes. The performance of the TEGs was studied for different temperature differences between ΔT = 10 and 70 K. Power output (P max ) levels of several microwatts and output voltages of several millivolts can be easily achieved.

Screen-Printed Flexible Thermoelectric Device Based on Hybrid Silver Selenide/PVP Composite Films

“…As an “electron crystal, phonon liquid” n-type material, silver selenide (Ag 2 Se) is environmentally friendly and abundant, with high electrical conductivity and low thermal conductivity at room temperature. It has become an ideal Bi 2 Te 3 replacement material and is the most promising n-type material in recent years [ 29 , 30 , 31 , 32 , 33 ]. Mallick et al initially prepared a flexible-folded TEG consisting of 13 thermocouples using screen printing with an output voltage of 181.4 mV at ΔT of 110 K, where Ag-Se ink was used as n-type leg and PEDOT:PSS as the p-type leg.…”

“…Mallick et al initially prepared a flexible-folded TEG consisting of 13 thermocouples using screen printing with an output voltage of 181.4 mV at ΔT of 110 K, where Ag-Se ink was used as n-type leg and PEDOT:PSS as the p-type leg. Later on, Ag-Se ink was applied to 3D printing, three shapes of samples were prepared, and the output voltage was 55 mV at 70 K [ 29 , 30 , 31 ]. To obtain n-type flexible thermoelectric devices with better performance, some researches have been conducted on composite organic and inorganic materials to make them flexible and to improve the thermoelectric properties of the composites [ 34 , 35 ].…”

Printed Thermoelectrics

“…Cu 2 Se has been shown to be spin coated, [83] Ag 2 Se to be printed, [84][85][86] and SnSe to be 3D printed. [36] Thermoelectric properties of these printed selenides are represented in Figure 12 (also Table S6, Supporting Information), along with images of the printed materials and schematics of manufacturing techniques.…”

Boosting the performance of printed thermoelectric materials by inducing morphological anisotropy

“…Many studies have reported inorganic TE slurries/powders that can be printed by SLM/SLS, 43,45,46 DIW [47][48][49] or stereolithography 50 to form ingots. Furthermore, the same materials can be formulated as inks, which can be directly painted onto 3D objects [51][52][53] or patterned on flexible substrates by inkjet printing, 42,54 aerosol jet printing, 53,55,56 dispensing, 57 or screen printing 52,[58][59][60][61][62][63][64] to form shape-conformable and flexible devices. However, the combination of those printing techniques with the search of morphological anisotropy to improve the final performance has been largely overlooked.…”