無鉛鈣鈦礦有望開啟壓電能量收集新時代

一組研究人員創建了一種充滿硫族鈣鈦礦化合物的聚合物薄膜，該薄膜在受到壓力時可以發電。

Researchers have created a polymer film filled with a chalcogenide perovskite compound that generates electricity when stressed. This phenomenon is known as the piezoelectric effect, which is simply the ability of certain materials to generate an electric charge when mechanical stress is applied.

研究人員創造了一種充滿硫族鈣鈦礦化合物的聚合物薄膜，該化合物在受到壓力時可以產生電力。這種現象稱為壓電效應，即某些材料在施加機械應力時產生電荷的能力。

The piezoelectric effect occurs in materials that lack crystal structural symmetry. Crystals, ceramics, polymers, and biological matter such as bone, DNA, and various proteins are different kinds of piezoelectric materials.

壓電效應發生在缺乏晶體結構對稱性的材料。晶體、陶瓷、聚合物和生物物質（例如骨骼、DNA 和各種蛋白質）是不同種類的壓電材料。

Such materials have the potential to collect the energy related to mechanical vibrations. The best thing about this form of energy is that it is present all around us in abundant supply and is renewable in nature.

此類材料具有收集與機械振動相關的能量的潛力。這種能源形式的最大優點是，它在我們周圍供應充足，而且本質上是可再生的。

However, as the latest research notes, piezoelectric materials that are best performing tend to have the chemical element lead (Pb), which can cause cancer, increase the risk of brain tumors, and hinder DNA repair.

然而，正如最新研究指出的那樣，性能最佳的壓電材料往往含有化學元素鉛 (Pb)，這種元素會導致癌症、增加腦腫瘤的風險並阻礙 DNA 修復。

Materials that contain lead are hazardous, and regulators have curtailed their use to protect the environment.

含鉛材料是危險的，監管機構已限制其使用以保護環境。

Given the toxicity of lead, which is a heavy, malleable, naturally occurring metal with a relatively low melting point, it is being increasingly phased out of materials and devices.

鉛是一種重的、有延展性的、天然存在的金屬，熔點相對較低，考慮到它的毒性，它正被越來越多的材料和設備所淘汰。

Hence, the team's goal was to create a material that was lead-free and able to be made inexpensively using elements that are commonly found in nature.

因此，該團隊的目標是創造一種無鉛材料，並且能夠使用自然界中常見的元素以廉價的方式製造。

So, the team from the Rensselaer Polytechnic Institute (RPI) made use of a material that not only does not contain lead but is also one of the few high-performing ones. Hence, it is a great candidate for use in biomedical applications, machines, and infrastructure.

因此，倫斯勒理工學院 (RPI) 的團隊使用了一種不僅不含鉛而且也是少數的高性能材料之一的材料。因此，它是生物醫學應用、機器和基礎設施的絕佳候選者。

The lead-free material that the team used belongs to the chalcogenide perovskite family exhibiting piezoelectricity. BaZrS3 was the composition used in the study, which is reported to have a pronounced piezoelectric response.

該團隊使用的無鉛材料屬於具有壓電性的硫族化物鈣鈦礦家族。 BaZrS3 是該研究中使用的成分，據報導它具有明顯的壓電響應。

Chalcogenide perovskites have been gaining a lot of attention and advances lately. This family of compounds is related to perovskite structures, which have many favorable properties such as low toxicity, high stability, direct band gaps, good carrier transport abilities, and strong light absorption.

硫屬化物鈣鈦礦最近受到了廣泛的關注並取得了進展。該類化合物與鈣鈦礦結構有關，具有低毒性、高穩定性、直接帶隙、良好的載子傳輸能力和強光吸收等許多有利特性。

These properties make perovskites really stand out in applications like photovoltaics, photodetectors, light-emitting devices, and photocatalysts.

這些特性使鈣鈦礦在光伏、光電探測器、發光裝置和光催化劑等應用中真正脫穎而出。

Interestingly, most high-performing piezoelectric materials are non-centrosymmetric and hence display intrinsically high polarizability. However, many oxide perovskites, including the one used in the study, exhibit a centrosymmetric crystal structure, which is weakly piezoelectric in its pristine form. These compounds are actually non-polar because they inherently lack a net dipole moment.

有趣的是，大多數高性能壓電材料都是非中心對稱的，因此表現出本質上高的極化率。然而，許多氧化物鈣鈦礦，包括研究中使用的氧化物鈣鈦礦，表現出中心對稱晶體結構，其原始形式具有弱壓電性。這些化合物實際上是非極性的，因為它們本質上缺乏淨偶極矩。

The dipole moment is the scientific name for the way piezoelectric materials perform when under stress, which is deformation in a way that causes positive ions and negative ions in the material to separate. This dipole moment can be harnessed and turned into an electric current.

偶極矩是壓電材料在應力下表現的科學名稱，即導致材料中的正離子和負離子分離的變形。可以利用該偶極矩並將其轉換為電流。

But with no net dipole moment, how did the team achieve piezoelectricity? Well, they leverage the loose packing within the chalcogenide perovskite structure to overcome the problem.

但在沒有淨偶極矩的情況下，該團隊是如何達到壓電性的呢？那麼，他們利用硫族化物鈣鈦礦結構內的鬆散堆積來克服這個問題。

Scaling the Technology for Green Energy Applications

擴展綠色能源應用技術

The latest study details that despite being centrosymmetric, lead-free chalcogenide perovskite materials become polarizable very quickly when it is deformed. This is due to a loosely packed unit cell, which has a lot of vacant space.

最新研究詳細說明，儘管無鉛硫屬化物鈣鈦礦材料具有中心對稱性，但在變形時會很快變得極化。這是由於單元電池結構鬆散，有大量空閒空間。

This significant volume of empty space allows extended displacement of ions, which, in turn, allows for the reduction of symmetry and results in an amplified displacement-mediated dipole moment.

這種巨大的空白空間允許離子的擴展位移，這反過來又允許對稱性的降低並導致位移介導的偶極矩的放大。

The team performed a piezoresponse force microscopy (PFM) on BaZrS3 to confirm the piezoelectricity of the material.

該團隊對 BaZrS3 進行了壓電響應力顯微鏡 (PFM)，以確認該材料的壓電性。

PFM is a functional atomic force microscopy (AFM) model that has been recognized for the unique information it offers on the electromechanical properties of various materials on the nanometer scale.

PFM 是一種功能性原子力顯微鏡 (AFM) 模型，因其在奈米尺度上提供各種材料機電特性的獨特資訊而受到認可。

Structural symmetry in the chalcogenide perovskite material, as per the team, can be easily broken under stress, which leads to an enhanced piezoelectric response. So, once confirmed, the team developed composites of BaZrS3 particles dispersed in polycaprolactone.

研究團隊表示，硫族化物鈣鈦礦材料的結構對稱性在壓力下容易被破壞，增強壓電響應。因此，一旦得到證實，該團隊就開發了分散在聚己內酯中的 BaZrS3 顆粒的複合材料。

The new material synthesized contains barium, zirconium, and sulfur, which were then used to harvest energy from human body motion and power electrochemical and electronic devices.

合成的新材料含有鋇、鋯和硫，然後用於從人體運動中獲取能量，並為電化學和電子設備提供動力。

The team tested the material's ability to generate electricity by subjecting it to bodily movements like running, walking, tapping fingers, and clapping. The electricity produced during the experiment was found to be enough to power LED banks, spelling out RPI.

研究團隊透過跑步、行走、敲擊手指和拍手等身體動作來測試這種材料的發電能力。實驗期間產生的電力足以為 LED 組供電，即 RPI。

“We are excited and encouraged by our findings and their potential to support the transition to green energy.”

“我們對我們的發現及其支持向綠色能源過渡的潛力感到興奮和鼓舞。”

– Nikhil Koratkar, Study co-author

– Nikhil Koratkar，研究合著者

The material, according to him, converts mechanical energy into electrical energy. According to Koratkar:

據他介紹，這種材料將機械能轉換為電能。根據科拉特卡的說法：

“The greater the applied pressure load and the greater the surface area over which the pressure is applied, the greater the effect.”

“施加的壓力負載越大，施加壓力的表面積越大，效果就越大。”

The energy harvesting film created by the team is just 0.3 millimeters thick and can be integrated into various machines, devices, and structures like buildings and highways to

該團隊製造的能量收集薄膜厚度僅為 0.3 毫米，可整合到各種機器、設備以及建築物和高速公路等結構中，