隨著手機、汽車和其他電力需求量較大的設備在我們的生活中日益普及，尋找更好的電池，可能會成為科技行業的終極軍備競賽。但華盛頓大學的研究人員或許已經顛覆了這個行業。研究人員宣布通過不使用電池的手機進行了首次蜂窩式通話。

這款原型機完全采用了市場上現有的零件，使用無線電源和小型太陽能充電器供電。當然這款手機確實非常簡陋：除了收發語音信號，支持一副耳機外，該手機沒有任何其他功能。既沒有屏幕也沒有內存。使用這款設備接通通話后，要按下一個按鍵才能開始對話。

它需要依靠附近的基站，將信號中繼到手機的蜂窩網絡。研究人員使用的是Skype。基站提供了手機的大部分運行電力，這些電力來自于無線信號。

這款手機可利用反向散射生成自己的信號。這項技術在無線射頻識別芯片中已經很常見，這種芯片在現有的無線信號中輸入新信息，然后反向反射到接收器中。

這款手機的一項重要創新是使用模擬語音編碼而非數字編碼，研究人員稱，模擬技術可以大幅節省電力。用來擴大手機信號范圍的補充電力，來自于光電二極管，實質上是一個微型太陽能面板。

簡而言之，短期內別指望能在這款設備上一直玩《糖果傳奇》。但研究人員預測，未來類似的無線技術將被廣泛應用到手機信號塔或Wi-Fi路由器當中，使無電池通話變得無處不在，當然前提是我們不會完全放棄語音通話，轉而選擇短信、Snap Stories或其他通信方法。

6月30日發表的一篇研究論文詳細介紹了這款手機。（財富中文網）

譯者：劉進龍/汪皓

The quest for better batteries may be the ultimate technology industry arms race as phones, cars, and other power-hungry devices proliferate in our lives. But researchers at the University of Washington may have upended that equation, making what they say is the first cellular call from a mobile phone with, well, no battery at all.

The prototype phone, built with off-the-shelf components, runs on a combination of wireless power and tiny solar chargers. It’s certainly barebones: the phone can send and receive voice signals, drive a pair of head phones, and not much else. It has neither screen nor memory. Once you connect a call using the device, you have to push a button to talk.

The phone must rely on a nearby base station that relays its signal to the cellular network, in this case via Skype. The base station provides the bulk of the phone’s operational power, which the phone harvests from radio signals.

The phone generates its own signal using backscatter, a technique already common in RFID—as in radio frequency identification—chips that encodes existing radio signals with new information and reflects them back to a receiver.

One of the phone's key innovations is the use of analog rather than digital voice encoding, which the researchers say saves a substantial amount of power. Supplemental power to increase the device’s range comes from photodiodes, essentially tiny solar panels.

In short, don't expect to play endless games of Candy Crush on this device anytime soon. But the researchers envision a future where similar wireless technology is widely integrated into cell towers or Wi-Fi routers, making battery-free phone calls ubiquitous—assuming, of course, that we don't give up on voice calls entirely in favor of text messages, Snap Stories, or other communications methods.

The phone is described in detail in a research paper published on June 30th.