SENSITIVE SKIN

This seminar focuses on the principles, methodology, and prototypes of sensitive skin-like devices, and the related system intelligence and software that are necessary to make those devices work. Sensitive skin represents a new paradigm in sensing and control. These devices will open doors to a whole class of novel enabling technologies, with a potentially very wide impact. Far-reaching applications not feasible today will be realized, ranging from medicine and biology to the machine industry and defense. They will allow us to fulfill our dream for machines sensitive to their surroundings and operating in unstructured environment.

Some applications that sensitive skin devices will make possible are yet hard to foresee. Flexible semiconductor films and flexible metal interconnects that will result from this work will allow us to develop new inexpensive consumer electronics products, new types of displays, printers, new ways to store and share information (like electronic paper and “upgradeable” books and maps). New device concepts suitable for large area flexible semiconductor films will lead to new sensors that will find applications in space exploration and defense, specifically in mine detection and active camouflage.

An ability of parallel processing of massive amounts of data from millions of sensors will find applications in environmental control and power industry. These areas will be further developed because of the highly interdisciplinary nature of the work on sensitive skin, which lies at the intersection of information technology, mechanical engineering, material science, biotechnology, and micro- and nano electronics. Availability of sensitive skin hardware is likely to spur theoretical and experimental work in many other disciplines that are far removed from robotics.

APPLICATIONS

HUMAN SKIN OR WEARABLE SKIN

Wearable sensor skins have started to appear in preliminary forms such as the Data Glove, which measures finger joint positions for human-computer interface (HCI). These wearable skins for HCI can be expanded to include body suits which not only measure joint angles, but could also measure and apply contact pressures, to give people a much higher dimensional and more natural interaction with computers. Obvious HCI applications are in training, education, and entertainment.

In the biomedical area, wearable sensitive skins can be used to restore sensory capability to people who have lost fine sensation in extremities (such as diabetics), or to people with spinal cord injuries. A relatively simple sensitive skin garment could be used to prevent pressure sores in bedridden or wheel chair bound people. A wearable sensitive skin would also be useful for overall physiological monitoring, such as frostbite detection. If the wearable sensitive skin can also include even a simple actuation capability, a very wide range of further biomedical applications becomes promising. For example simple distributed actuators could be used in applications such as thermoregulation, functional neuromuscular stimulation, smart compression for lymphatic system drainage, or controllable damping/stiffness for tremor reduction. Of course, the sensitive skin is not limited to the strain, vibration, and temperature senses of human skin. Proximity sensing would be a useful capability for the visually impaired. For military applications, sensors for laser, radar, chemicals, or puncture would be quite valuable. By 2010, the "dream soldier will have sensors built into a skintight uniform." After 10 years, every piece of clothing will include some electronics,"

SENSITIVE SKINS FOR MACHINES

If machines are to work nimbly in cluttered environments or with humans, they need sensitive skins with proximity and contact sensors. These sensors would provide information so the machines could protect both themselves and people they work with. For human-computer interaction, robot companions could respond appropriately to human touch. Moving vehicles could have an intelligent skin, which allows easier navigation in tight spaces, for example maneuvering automobiles on crowded streets.

ENVIRONMENTAL SENSITIVE SKIN

Even fixed structures as simple as floors and walls could have improved functionality using a low-cost sensitive skin. For example, a floor with distributed pressure sensors could be used for tracking, or a safety measure to warn of slippery spots or report falls. In civil engineering, skins for buildings and bridges can warn of fatigue or impending failure. For human computer interaction, surfaces could respond to gestures and infer intent, such as changing a lighting level.

ACTUATED SENSITIVE SKIN

There is overlap between applications of passive sensitive skin and the whole area of active surfaces such as drag reduction in aero- and hydrodynamics. For example, active surface furniture such as chairs could increase comfort for people sitting for long periods of time. Active sensitive skin on walls could be used for sound and vibration canceling.

CONCLUSION.

Sensitive skin is a large array of sensors embedded in a flexible, stretchable, and/or foldable substrate that might cover the surface of a moving machine. By endowing these machines with ability to sense their surroundings, sensitive skin will make it possible to have unsupervised machinery in unstructured, unpredictable surroundings. Sensitive skin will make the machines “cautious” and thus friendly to their environment. With these properties, sensitive skin will revolutionize important areas of service industry, make crucial contributions to human prosthetics, and augment human sensing when fashioned into clothing. Being transducers that produce and process information, sensitive skin devices will be generating and processing data flows in real time on a massive scale, which will lead to yet another leap in the information revolution. Sensitive skin presents a new paradigm in sensing and control. It is an enabling technology with far reaching applications, from medicine and biology to industry and defense. The state of the art in the areas that are basic to development of the skin technology shows that highly efficient devices should be feasible, meaning by this high density of sensors on the skin, and hierarchical and highly distributed real time sensor data processing. All this non withstanding the fact that the existing prototypes are clumsy, have low resolution, accuracy and reliability, and are not yet ready for commercialization. Serious research issues elaborated in this paper have to be resolved before sensitive skins can become a ubiquitous presence in our society. We hope the readers will view this paper as our first effort to map out the new territory, and as an invitation to join in the exploration.