Self-powered temperature-changing system driven by wind energy

With the continuous development of society, heating and cooling processes consume more natural energy than before. Conventional cooling and heating processes are usually performed with compressors driven by electrical energy to control the Free phase change characteristics; these processes often consume considerable amounts of power1–3. As the total amount of fossil fuel energy consumed on Earth is decreasing, it is highly important to find a new self-powered technology4–6. Triboelectric nanogenerators, which were proposed by the academic Zhonglin Wang, can convert various forms of mechanical energy in the environment, such as wind7–9, wave10–12, water droplet13–15, and human body movement energy sources, into electrical energy16–18. With the advantages of a low production cost, a convenient transmission ability, and an excellent low-frequency energy harvesting effect, this technology has attracted extensive attention in many fields, such as sensors19, medicine20, agriculture21, and artificial intelligence22. In addition, TENGs are self-powered technologies. These nanogenerators provide new contributions to research on functional materials (e.g., ferroelectric materials and thermoelectric materials) in temperature-variable devices. The Seebeck effects of thermoelectric materials and the electrothermal effects of ferroelectric materials are the foundational effects underlying the research and development of devices that can change temperatures. The Seebeck effect requires a stable high current (more than 1A) to serve as the basis; thus, this effect is not currently realized by TENGs. In contrast, ferroelectric materials only need a high electric field to induce stable electrothermal effects. Therefore, combining the high-voltage outputs of TENGs with the electrothermal effects is perfect for realizing self-powered cooling and heating processes. Research on electromechanical transducers has been conducted for decades, and many scientific researchers around the world are committed to preparing electroelectrical materials with high EC performance characteristics. The 350-nm PbZrxTi1−xO3 thin film prepared by Mishchenko and other researchers has a large electrocaloric effect at room temperature: ΔT = 1.2 K. Peng and other researchers have prepared lead-free ferroelectric ceramics, which greatly reduce the damage to the environment. In 2022, Li and other researchers first proposed the use of TENG and PST ceramics to realize self-poweredelectrocaloric refrigeration. In 2023, researchers, including our group, established that TENGs could reach a cooling power of 4.2 W under a moderate electric field of 10 V m−1 at 20.9 K. The cooler reaches a maximum cooling power of 4.2 W under a moderate electric field of 10 V m−1 at 20.9 K. On the one hand, due to the shortcomings of TENGs in the vertical separation mode, such as low voltage and slow charge accumulation, they can quickly create ceramic chips with adequate electric field strengths. On the other hand, the comprehensive performance characteristics of the ferroelectric ceramic materials used in the experiment, including energy capture and electrocold performance, still have room for improvement. Therefore, it is highly important to develop thermoelectric nanogenerators with fast charge accumulation and high-voltage outputs ability and ceramic materials with improved energy capture performance characteristics. For the first time, this work presents a self-powered temperature-quantifiable control device (SPT 1.0) with a tunable structure. To accommodate the high electric field strength required for the ceramic chip to exert the electrothermal effect, an FEP–rabbit for rotating turntable TENG is used. An ultrahigh open-circuit voltage of 6913 V at 240 pins can be obtained by driving the continuous rotation of the turntable via wind energy. With only six 0.15PST–0.85PST ceramic chips, this experimental phenomenon is achieved beyond the 12 PST ceramic chips used in studies by Li and other researchers. A temperature change of 0.49 K is achieved in a space 300 times greater than the volume of the ceramic chips, which is an 81% improvement in the temperature change at room temperature. Moreover, the time required for cooling/ heating is only 276 s, which is a 31% reduction. Furthermore, by increasing the number of ceramic pieces and adding cooling components, an optimized SPT of 2.0 increases the heating and cooling temperatures to 1.19 K and 0.93 K, respectively, confirming the commercialization of the device. Here, we only propose an application scenario for agricultural production. The system collects and converts energy from the variable natural environment into electricity, thereby controlling the temperature of the agricultural greenhouse. A solution is proposed for energy consumption due to cooling and heating during agricultural production.

The introduction surveys prior work on electrocaloric materials and TENG-driven cooling. Mishchenko et al. reported a 350-nm PbZrxTi1−xO3 thin film exhibiting a room-temperature electrocaloric temperature change of ΔT ≈ 1.2 K. Peng and colleagues developed lead-free ferroelectric ceramics to reduce environmental impact. In 2022, Li et al. first combined a TENG with PST ceramics to realize self-powered electrocaloric refrigeration. In 2023, the authors’ group reported that TENGs could achieve a cooling power of 4.2 W under a moderate electric field of 10 V m−1 at 20.9 K. However, conventional vertical contact-separation TENGs suffer from relatively low voltage and slow charge accumulation, and prior ceramic systems left room for improvement in energy harvesting and electrocaloric performance, motivating the present work.

Experimental procedures: The self-powered temperature-changing system comprises energy-collecting wind cups, a rotating disc-shaped FEP–rabbit fur TENG (rotor/stator), a circuit management module, and a ferroelectric ceramic chip array. The wind cup (light acrylic) couples through a bearing to the rotor covered with rabbit fur. The stator is a customized disc with patterned copper electrodes laminated with FEP film. During operation, wind drives continuous rotation. Contact electrification between rabbit fur and FEP charges the FEP negatively; potential differences between electrodes A and B drive alternating charge flow through the external circuit as rabbit fur sequentially covers/un-covers electrodes, producing an AC high-voltage output. The working sequence cycles as the fur moves from electrode B to A and back, alternately inducing current directions as potential on each electrode rises/falls. Thermal-electric circuit: The TENG output is conditioned by a circuit management module to bias the ferroelectric ceramic chip array with a high electric field, inducing electrothermal (electrocaloric) heating/cooling in the target volume (e.g., an insulated cup). Materials and characterization: Ferroelectric ceramics based on Pb(Sc0.5Ta0.5)O3–Pb(Ti, Zr)O3 compositions (nominally 0.15PT–0.85PS/PST) were synthesized and subjected to quenching treatments with times of 10–50 h. Structural characterization included XRD (monitoring (100), (110), (111), (200), (211), (220), (310) reflections) showing phase stability with/without quenching and absence of impurity peaks. Raman spectroscopy exhibited six characteristic peaks (≈100, 200, 300, 500, 700 cm−1, etc.) consistent with stable phase structures and polar cluster features. SEM imaging showed dense microstructures with tightly packed grains; grain size increased with quenching time. Electrical measurements: Polarization–electric field hysteresis loops were measured at 1 Hz over 303–423 K. Unquenched 0.15PT–0.85PT showed a sharp, wide loop at 303 K with maximum polarization ≈34.4 μC/cm², decreasing with temperature to ≈14.9 μC/cm² at 423 K. Among quenched samples, 40 h quenching yielded the highest polarization at both 303 K and 423 K. Device-level tests: The rotating disc TENG (up to 240 pins) harvested wind energy to generate ultrahigh open-circuit voltage. The conditioned output drove an array of six 0.15PT–0.85PST ceramic chips to modulate temperature in an insulated cup volume ≈300× the ceramic volume. System performance was evaluated at rotor speeds around 200 rpm, recording temperature transients for both heating and cooling.

- The rotary disc-shaped FEP–rabbit fur TENG achieved: maximum open-circuit voltage ≈ 6913 V; maximum short-circuit current ≈ 85 μA; maximum transferred charge ≈ 1.3 μC. - Synthesized ferroelectric ceramic (0.15PT–0.85PST) exhibited room-temperature electrothermal performance enhanced by quenching: ΔT_max ≈ 1.574 K; energy harvesting density ≈ 0.542 J/cm³. - Self-powered temperature-quantifiable control system (SPT 1.0) with six ceramic chips converted wind energy (≈200 rpm) into a high-voltage electric field, producing a temperature change of ≈0.49 K in an insulated cup (at 300 K) within 276 s. - Relative to prior benchmarks, cooling and heating times were reduced by ≈31%, and the magnitudes of both cooling and heating temperature changes increased by ≈81%. - An optimized system (SPT 2.0), achieved by increasing ceramic chip count and adding cooling components, attained heating and cooling temperature changes of ≈1.19 K and ≈0.93 K, respectively. - Materials characterization confirmed stable crystal structures across quenching times (no impurity phases) and dense microstructures with grain growth upon longer quenching; electrical hysteresis loops showed strong polarization at 303 K with temperature sensitivity and optimal performance for 40 h quenching.

The study demonstrates that combining an ultrahigh-voltage, fast-charging rotary disc TENG with electrocaloric ferroelectric ceramics enables a fully self-powered temperature control system driven by ambient wind. By addressing limitations of vertical contact-separation TENGs (insufficient voltage, slow charge accumulation) and optimizing ceramic processing (quenching to boost electrothermal response), the system delivers measurable heating/cooling in a volume far exceeding the ceramic volume (≈300×) while operating at room temperature. The use of only six chips to achieve 0.49 K change (and >1 K after optimization) underscores improved device efficiency compared to earlier implementations (e.g., requiring 12 chips). These results validate the feasibility of TENG-driven electrocaloric temperature modulation for practical scenarios, such as greenhouse climate control, contributing to reduced dependence on compressor-based HVAC and aligning with carbon reduction goals. The significant improvements in time-to-effect and temperature swing highlight the relevance of the approach for mobile and outdoor applications where grid power is limited.

This work introduces a self-powered, wind-driven temperature-changing system that integrates a high-voltage rotary disc FEP–rabbit fur TENG with optimized 0.15PT–0.85PST electrocaloric ceramic chips. The TENG delivers up to 6913 V and, together with quenched ceramics exhibiting ΔT_max ≈ 1.574 K and energy density ≈ 0.542 J/cm³, enables quantifiable heating/cooling: 0.49 K shift in 276 s at room temperature using six chips, with an optimized configuration reaching 1.19 K (heating) and 0.93 K (cooling). Structural and electrical characterizations confirm stable phases, dense microstructures, and strong polarization with temperature sensitivity. The system’s performance advances self-powered thermal management and suggests potential for commercialization and applications such as agricultural greenhouse temperature regulation. Future work can further enhance performance by scaling chip arrays, refining circuit management and thermal design (e.g., added cooling components), and harvesting diverse ambient mechanical energies (wind, water) for broader deployment.