High performance wearable thermoelectric coolers with 3D structural thermoelectric pillars

Maintaining body temperature near 36 °C is vital for physical and mental health. High temperatures and intense activity can overwhelm natural thermoregulation. Personal cooling garments offer a promising solution, but current designs are either ineffective or too bulky. Thermoelectric coolers (TECs) show potential, yet most rely on straight TE pillar configurations, limiting cooling due to low ZT values. A key trade-off exists: longer pillars reduce thermal conductance and enhance cooling, but reduce wearability. As a result, most wearable TECs are limited to ~ 10 °C cooling. Here, we present a TEC design using 3D structural pillars, enabling longer effective length without increasing device height. This balances cooling performance and wearability. With inner air removed, the device achieves ~ 30 °C cooling and improved coefficient of performance (COP). Our work significantly advances wearable TEC performance by overcoming limitations of conventional designs and offers a path toward practical high-performance personal cooling.