Radio Frequency (RF) energy surrounds most of us in the modern world on an almost constant basis. This presents challenges from two perspectives. From a human perspective, few people would say that they have absolutely no concern whatsoever regarding the radio waves that play a role in their lives. From a commercial perspective, the engineers that design RF into myriad equipment and the companies that operate them need them to be efficient and cost effective to build and to use.
Considering first the human impact of so much RF energy surrounding us, few researchers have been bold enough to tell people that their cell phone is hurting them. However, in late 2017, the California Department of Public Health published guidelines for their use. By no means a "smoking gun" it does still give even skeptics reason to give the issue some thought.
From a commercial perspective, it is not unexpected that cost is a major driver. Devices that use RF technology to communicate must do so efficiently while using the least amount of electrical energy possible. If those goals can be achieved while adding an element of safety they achieve the classic "win-win."
RF Energy Redirection is actually a broadly used term for an approach that has for many years played at least some role in the design of antenna systems ranging from the radio telescope to today's cell phone towers: redirect the radio waves where you want them. New materials are making those systems better and making new applications possible.
A client needed a material to enable an after-market screen protector to redirect RF energy away from smartphone users. It is common to laminate multiple layers of glass and plastic films to ensure that a screen protector is not only protective but also provides other enhancements; for example, privacy. What is uncommon, however, is a material that can interact with the RF energy while not disrupting the projected capacitive (PCAP) touchscreen. To accomplish this, CHASM produced a patterned film using a high sheet resistance carbon nanotube ink applied to polyester. The resulting screen protector redirects up to 95% of RF energy away from the smartphone user.