Triboelectric nanogenerators (TENGs), a groundbreaking Israeli development, is giving hope to people who have lost their sense of touch due to amputation. A unique sensor is implanted in the injured area and, upon contact, creates an electric signal that flows directly to the healthy nerve, restoring tactile sensation
A white foam, waves caressing the shore, and two friends running together along the waterline – that was the point of departure for a fascinating scientific quest that could improve the lives of countless people whose neural sensations have been damaged as the result of amputated fingers, and serve as the foundation for numerous other developments.
“I went for a run along the beach”, says Prof. Ben Maoz from the Department of Bio-Medical Engineering at Tel Aviv University’s Sagol School of Neuroscience. “My running partner, Dr. Amir Arami, Head of the Hand Surgery and Microsurgery Department at the Sheba Medical Center shared a professional frustration: we have the ability to restore patients’ severed fingers, but not the feeling in them, and the loss of sensation is significant according to any parameter”. Prof. Maoz listened and replied: “challenge accepted”, and the two embarked on a mission – to develop a solution that will restore sensation to damaged nerves.
From Static Electricity to a Medical Breakthrough
The clinical need led to the development of a revolutionary device, the Triboelectric Nanogenerator (TENG) – a pressure sensor that is attached to the end of the damaged finger. “It sounds wonderfully simple”, says Prof. Maoz. The device consists of two miniature plates that touch each other, creating electric voltage between them. When pressure is applied to the plates, these layers rub against each other and create electricity”.
In other words, the level of electric pressure created corresponds to the force of the pressure being exerted on the sensor. The sensor does not rely on an external power source or a battery but rather, utilizes an effect of static electricity to create an electric signal. “A higher level of pressure results in a higher voltage”, Prof. Maoz explains. “The range of pressures to which the device is sensitive fluctuates between the touch of a feather and the pressure of a clenched fist, and the voltage created is tuned in such a way that it will stimulate the nerves”.
The Technology Behind the Magic: Triboelectric Nanogenerators
The technology behind this revolutionary development is called triboelectric nanogenerators (TENGs) – a technology that uses devices capable of harvesting energy for converting mechanical movement into electric energy.
These devices are made up of active materials that create electric charges, and a conductive electrode responsible for harvesting and transferring the charges. The word “nano” refers to the tiny size of the generators that produce electricity, and the word “triboelectric” relates to the process of creating electricity via friction.
Prof. Maoz notes that the first use of a self-charging device with static electricity was about ten years ago at Georgia Tech, as a means to harvest traditional and green energy. In other words, the innovation is not only in the technology’s development but “also in the fact that we have taken it from the worlds of materials and energy and adapted it to the worlds of biology and physiology”.
In practice, the development attaches the sensor to a healthy nerve that transfers the signal and the sensing. In other words, although the nerve is severed, the sensor acts as a kind of “extension cord” to the severed nerve and enables tactile sensation. This capability can significantly enhance the function and quality of life of people with injured limbs and nerves but also protect them from danger, because people who have no sense of touch cannot, for example, feel when their finger is crushed or injured.
The device is implanted underneath the skin in a simple operation that lasts less than an hour. It is not intended to be used as a first aid treatment but rather, as a solution for cases where other biological solutions of connecting nerves are unsuccessful. The scientists note that this technology is adjustable to the person’s body and can be implanted anywhere in it.
From Startup to Clinical Trials
In order to transfer the technology from the lab to the real world, Shai Feinsod, an experienced biotech executive, established the ‘Tengable’ company as part of a technological incubator. “The Innovation Authority invested in the company and this enabled us to proceed to clinical trials”, says Maoz.
The development received Innovation Authority investment with the aim of expediting the process and bringing forward the technology to a product stage as fast as possible for the benefit of the patients.
“We are continuing to raise funds”, Maoz explains, “and have even commenced the regulatory process via a company that works with the FDA. We expect to receive regulatory approval quickly because our development is not life-threatening and also because it falls under the category of products that enhance the quality of life i.e., there are no possible negative effects.
From the Lab to the Real World
The development, that began as a solution for a specific problem, quickly demonstrated much greater potential. “Two years ago, following the publication of our study, people started contacting us with problems we hadn’t conceived”, Prof. Maoz says. “Women who had undergone a mastectomy or breast reconstruction, diabetes patients who suffer from loss of feeling in different organs. Suddenly, we realized that the ‘market’ is much larger than we had initially thought”.
The harsh reality since October 7 only serves to re-emphasize the urgent need for these sensors. Numerous soldiers and civilians have been injured, lost limbs or suffered nerve damage, and need a solution that can restore their sensory ability.
“So far, we have conducted tests on mice”, says Prof. Maoz. “Their sensory ability was restored without any infection or inflammation. The next stage is tests with larger animals and humans”.
The team hopes to complete animal testing by the end of 2025 and to commence human trials stages within 2-3 years after that. “Our vision is very practical”, Prof. Maoz emphasizes, “we started as a response to a clinical need and we want to complete the job and bring the device to the clinic. Our goals are very clear, and we are making every effort to achieve them”.
Despite the impressive progress, the path to advancing the technology to clinical use remains long. “We are facing significant challenges”, Prof. Maoz admits. “We have to guarantee the sensor’s durability over time, develop precise surgical protocols, and overcome all the regulatory obstacles”.
Nevertheless, the technology’s potential is garnering significant interest among the medical and scientific communities. There is an understanding at medical centers and research institutes around the world that this technology may change the face of reconstructive medicine.
Beyond the direct medical impact, this development demonstrates the power of multidisciplinary research. “This shows what can be achieved when engineers and physicians work together”, says Prof. Maoz and expresses hope that this project will encourage further collaborations between the fields of engineering and medicine”.
When asked about the long-term vision, Prof. Maoz sounds optimistic but cautious. “We hope that within a decade, this technology will be available at clinics worldwide. But we still have a lot of work ahead of us. Every step forward brings new questions and challenges”.
Ultimately, behind all the advanced technology and scientific terminology stands a simple desire: to give people the ability to feel the world around them again. “To touch and feel. To hold the hand of a loved one, to pet the dog, to feel the sand between their toes”, says Prof. Maoz. These are things we take for granted until we lose them”.
From a run on the beach to a technology that can change lives – this is evidence of the strength of innovation and of the importance of collaboration between doctors and engineers. The development of Prof. Maoz and Dr. Arami offers new hope – not just to restore physical sensation, but also to give people the ability to fully experience the world again.
Future Implementations: Beyond Severed Fingers
Aviv Zeevi, VP & Head of Technological Infrastructure Division at the Innovation Authority, sees tremendous potential in this technology. “Among other reasons, developing sensors of this kind is challenging because of the need for long-term durability and reliability”, he explains. “But such sensors can serve in a variety of other fields such as robotics, medical devices, textile, or advanced man-machine interfaces”.
Zeevi adds that “the TENG enables energy independence and flexibility in the structure and size of the devices. The nanometric dimensions open future possibilities to integrate the TENG in miniature devices such as biological chips or micro-electromagnetic systems, and to lead to the development of innovative devices and sensors, advanced touch interfaces, and the creation of complex networks of sensors for environmental or industrial monitoring. “The investment in such projects is an investment in the future of us all”, Zeevi emphasizes, “not just for healthcare applications, but also for fields such as environment, food, energy, and others, that can benefit from energy independence”.