- p- and n-type materials with high thermoelectric performance (PF: 270 μWm-1・K-2 <)
- Can be applied by inking
Product DescriptionCarbon Materials Dispersion Technology + Hybrid Technology
As the push toward creating an IoT and a trillion sensor society accelerates, the Toyo Ink Group proposes a sustainable self-powering systems that convert minute thermal energy such as exhaust heat from factories and body heat into electricity.
By using our printable organic materials, our researchers have developed thermoelectric materials that exhibit excellent processability and usage versatility, and can be applied to various situations such as flexible curved surfaces and wearable electronics.
Product Features
Product Characteristics: Organic vs. Inorganic Thermoelectric Modules
Although their output power is smaller than that of inorganic devices, Toyo Ink Group’s organic modules exhibit high integration, light weight and flexibility of the printing process, making it possible to save space, arrange curved surfaces, and implement wearable devices.
| Developed products (Organic thermoelectric module) |
Conventional products (Inorganic thermoelectric module) |
|
|---|---|---|
| Output （At 25℃ / 80℃ temperature difference） |
μW | mW |
| Output voltage (At 25℃ / 80℃ temperature difference) |
1V | 0.12V |
| Weight | 5.3g | 22.5g |
| Occupied volume | 3.6cm3 | 6.1cm3 |
| Flexibility | Good （No degradation in performance when r = 0.5 to 2 cm wrapped） |
Poor |
| Printing Process | Suitable | Not suitable |
Applications
Example 1: Self-powered systems for various edge sensors
Application image: Power source for smart factories and infrastructure sensors
Example 2: Wearable sensors
Application image: Skin for robots, environmental sensors
Technology OverviewHybrid Technology + Dispersion Technology of Carbon Materials
The Toyo Ink Group has developed organic thermoelectric conversion materials with excellent flexibility and printing characteristics (patterning, large area) and is in the process of applying prototype materials in the creation of thermoelectric conversion modules. Our researchers focused their attention on materials engineering and adopted carbon nanotubes (CNTs) with excellent thermoelectric properties and high electrical conductivity. By combining them with our proprietary organic materials, we were able to further improve CNT properties. The performance of the new thermoelectric conversion materials is evaluated by the power factor (PF: power generated per unit temperature difference). The PF value is obtained from the product of the Seebeck coefficient that indicates the electromotive force per unit temperature difference and the electrical conductivity. However, there is usually a trade-off between Seebeck coefficient and conductivity. To address this issue, we achieved high PF values by combining both Seebeck coefficient and conductivity at a high level by leveraging our unique hybridization technology that enhances the electronic interaction between CNTs and organic materials, and our CNT dispersion technology that constructs an optimal conductive path in the coating film.
PF：Power Factor (W/mK2)
S：Seebeck coefficient (V/K)
σ：Conductivity
Hybrid Technology
・Energy level control
We specially engineered the HOMO/LUMO energy levels of the organic materials for greater control of the electronic interactions such as the charge carrier transfer between carbon and organic materials.
・Adsorptive property control
By incorporating skeletons that interact with carbon materials, we can improve the adsorptivity to carbon materials and enhance the hybrid effect.
Improve thermoelectric performance by enhancing the electronic interaction between carbon and organic material.
Carbon Materials Dispersion Technology
By controlling the carbon material in an optimal dispersion state using our original dispersant and formulation, we achieved high conductivity (mobility) by inking the thermoelectric material and optimizing the conductive path in the coating film.
SEM image of coated film
Ink dispersion viscosity
Enhancing Electron Interaction between Carbon and Organic Materials to Improve Thermoelectric Performance