In these times of pandemic lockdowns, many of us dream of walking on a beach at sundown, feeling the sand under our toes and hearing the soothing pulse of the surf. Even if you’re lucky enough to have a virtual-reality (VR) headset, such a simulated experience doesn’t come close to the reality. But advances in materials and devices that can interface intimately with the body hold the promise that VR, and the related technology of augmented reality (AR, where our regular experience of the world is enhanced or modified), could be ever more realistic.

Most current visions of the VR technologies of the future look clunky. In Steven Spielberg’s 2018 movie Ready Player One, much of the world’s post-catastrophe population seeks consolation in VR games with total sensory immersion — but the experience requires people to put on cumbersome suits and headgear. A review article by Jae Joon Kim, Yan Wang and colleagues at the University of Tokyo1 offers a very different picture. They describe the state of the art in electronic devices that can be laid directly on the skin, simulating sensations of touch, transducing sound, and monitoring movement and physiology, all potentially controlled by wireless telecommunication such as Bluetooth and powered by harvesting ambient energy such as light or the body’s own metabolism and motion.

In the past decade, leaps have been made in methods for producing soft, flexible and non-toxic electronic circuits that can be laid directly on the skin2. Kim et al. describe how such techniques and materials might be used to make the components of VR systems, ranging from throat-mounted acoustic sensors that act as microphones3 and tactile sensors and actuators4 (for example conveying a sensation of touching physical objects with the fingertips) to biomechanical5 and photovoltaic6 power sources and strain sensors7 that will register posture and movement. On-skin displays using polymeric light-emitting diodes8 might be a component of interfacing, although ultimately smart contact lenses would replace bulky headsets for visual input. One alternative to on-body power might be wireless energy transmission, which has already been demonstrated for skin-mounted sensor systems9 — as has wireless data transmission using low-power near-field communication10 and Bluetooth.

Nearly all of the elements of a technology like this are, then, already in place. Whether they can all operate together with sufficient efficiency and sensitivity is another matter, let alone how a skin-mounted system could be constructed that can be robustly donned and removed.

In truth, consumer VR/AR would be one of the less socially useful applications of such technologies, which might for example also extend the capabilities of remote surgery, robotic control, and education, not to mention the possibilities for medical prostheses. But there’s no denying that consumer demand can be a major driver of technological innovation, as amply demonstrated by portable electronics and information technologies. At the same time, those developments show that such demand, and corporate profit motives, don’t always steer technologies in socially beneficial or ethical directions. Some of the possibilities for abuse of and addiction to technologies this compelling are obvious (it’s not hard to guess, given the trends on the Internet, what directions an intimately full-body VR experience might take). If ever there was a technology that urgently called for ethical debate before it hits the market, this is surely it.