據科技網站Computerworld報道，手機無時無刻不在發射無線電信號，無線電信號的能量可以被用來提升手機電池續航時間。

美國俄亥俄州立大學研究人員已經開發出能把手機發射的無線電信號轉化成電能的電路，然后把電能充到電池中。研究人員稱，這一技術能使手機電池續航時間延長至多30%。

俄亥俄州立大學在與創業公司尼古拉實驗室(Nikola Labs)合作，實現商業化。他們稱，該技術能方便地部署在手機殼內。

在科技博客網站TechCrunch本月早些時候舉辦的Disrupt會議上，尼古拉實驗室展示了一款能收集能量的iPhone 6外殼。尼古拉實驗室估計這款外殼的價格為99美元。

電池的限制使得能源收集技術受到關注，能源收集技術可以為可穿戴設備、傳感器等設備提供電能。大學和科技公司的研究人員紛紛研究把人體散發的熱量、運動、射頻信號和環境光轉化成能源的技術。

俄亥俄州立大學的技術需要一個天線收集無線電信號，一個整流器把收集到的信號由交流電轉換為直流電，然后給電池充電。俄亥俄州立大學稱，這一技術從無線電信號中獲得電能的功率可以達到數微瓦。

俄亥俄州立大學指出，其技術能從無線電信號中獲得電能延長電池續航時間，但不會影響手機通話質量或數據連接速度。(編譯/霜葉)

原文參考：

Radio signals can be used to boost cell-phone battery life

Ohio State University researchers are working with startup Nikola Labs to commercialize the technology

By Agam Shah

Cell phones are constantly transmitting radio signals, whose energy can also be used to boost the battery life of mobile devices.

Researchers at Ohio State University have developed circuitry that converts radio signals from a handset into energy, which is then fed back to the device's battery. The researchers say the technology can increase the battery life of mobile devices by up to 30 percent.

The OSU researchers are working with startup Nikola Labs to commercialize the technology, which they say can be easily implemented in cell-phone cases, and in June will launch a Kickstarter campaign to fund its continued development.

Nikola Labs pitched the concept of an energy-harvesting iPhone 6 case based on the technology at the TechCrunch Disrupt conference earlier this month. Nikola Labs estimates the case will be priced at $99.

Limitations in batteries have sparked an interest in energy-harvesting technologies to power battery-free wearables, sensors, implants and other devices. Researchers at universities and technology companies are looking for ways to convert body heat, motion, RF signals and ambient light to energy.

The technology developed by OSU has an antenna to capture the radio signals and a rectifier to convert them from AC into DC power, which is used to recharge a battery. OSU claims the circuitry can squeeze microwatts of power out of radio signals.

The technology kicks into action when signals are transmitted from a mobile device's radio, which itself can be a battery hog because a certain amount of energy is needed to maintain a high-quality signal with a cell-phone tower. However, OSU says its technology siphons off enough power to boost battery life without hurting the quality of phone conversations or data connections.