The advances of transistor count and density as predicted by Moore’s law in 1965, which states that the number of transistors per chip is doubled every 18 or 24 months, have pushed forward computers to be more powerful and miniaturized throughout the years. Gordon Bell in 1972 complemented this prediction, by arguing that “roughly every decade, a new, lower priced computer class forms based on a new programming platform, network, and interface resulting in a new usage and the establishment of a new industry”. We have experienced so far the computing classes evolution, from having a server in every establishment, a computer in every household, to one phone per individual. As electronics miniaturization in size and cost further progresses exponentially, we will be living around a hundred, a thousand, to tens of billions of wireless, smart sensor networks or electronic nervous systems in the following decades. We will step into, living in, walk around or surrounded by computers as they form the basis of our built environments, and in contrast, computers will also begin to roam inside us.
For these future smart computers, besides having signal and data processing capabilities, they would need to gain energy and interact with us and the environments through sensing, actuation, as well as fluidic networks of biological system. Therefore, they would not only need transistors for computational purposes, but they will also need to incorporate passive and active circuits, novel materials for sensors and actuators, batteries, and energy harvesting systems all packaged as a micro-electromechanical system (MEMS). Efforts in further miniaturizing a compact electronic system will follow (More Moore). In addition, the development of disruptive technologies that include heterogeneous 3D integration of multi-functional electronic modules, as well as new packaging techniques for MEMS (More-than-Moore), will enable a truly intelligent microsystems that could interact with the environments seamlessly.
The concept of pervasive or ubiquitous computing in the background has been popularly introduced by Mark Weiser in 1999, in his article “The Computers of the 21stCentury”. He states that “The most profound technologies are those that disappear. They weave themselves into the fabric of everyday life until they are indistinguishable from it”. In the future, people will unconsciously use technologies to accomplish their tasks and needs as hardware systems become invisible to their common awareness. As communication technologies evolved, research and developments in connecting people, media, data, and processes flourished, creating the term of the Internet of Things (IoT), Internet of Everything (IoE) and Big Data. However, in order to realize this vision of ubiquitous computing, further efforts in electronics everywhere, or seamless electronic nervous systems as a backbone must be realized.
Working towards the ubiquitous computing ecosystem and inspired by science fiction authors such as Stanislaw Lem, Neal Stephenson, and Vernor Vinge, low-power, miniaturized systems as small as a dust for military application purposes was conceptualized in 1992 as “Smart Dusts” by DARPA, UCLA, and University of Michigan. The sensor nodes were estimated to be 1-2mm in width and consist of passive CCR MEMS/polysilicon communication module, MEMS sensors, active beam steering laser communication and diode, Analog I/O, DSP, and control customized CMOS die, power capacitors with multi-layer ceramics, solar cells, and sol gel thick film battery at the bottom. Pister and Kahn from UC Berkeley realized a prototype of this concept in 2001 with their millimeter-scale sensor nodes. The sensor node is coin-cell size with length and width of 7 and 4 mm respectively. It is a self-powered system capable of sensing and communicate independently. It is envisioned that future version of these nodes could be small enough to be suspended and fly away by air currents, and can run for hours or days through solar energy harvesting.
The inspirations of these Smart Dust technology and their applications came from science fiction novels such as The Invincible (1973), The Diamond Age (1986), and Prey (2002). In the Invicible, the idea of very small, insect-like, micro-robots that are intelligent and can swarm was introduced. They are harmless individually, but they could become deadly as they assemble into a big army of bees or as a “cloud” and travel in a high-speed. Prey by Michael Crichton also was written with similar concept of deadly swarm nanobots that fuse nanotechnology, generic engineering and biological evolution. Another smart dust concept was covered in the Diamond Age. Neal Stephenson introduced the Matter Compliers and exemplified the possible future from advances in nanotechnology and digital manufacturing. On the other hand, several science fiction works inspired by nanotechnology and swarm intelligence include Big Hero 6 and Black Mirror.
Technology: Electronic Particle
Since Pister et al.developed the first Smart Dust prototype in 1999, advances in materials, micro and nanofabrication technologies, and 3D packaging techniques have enabled further miniaturization of full Smart Dust system. Some examples include RF or optical communication, single modality sensor such as temperature, pressure, glucose level, or electrophysiology with low-power system in the range of 1 nW to 50 μW. An example is 360 by 400 μm Smart Dust, developed in 2019 that is 500 times smaller than a grain of rice. Extrapolating from the trend, it can be predicted that by 2050, Smart Dusts will have a size in the range of sub-um, and by 2100, they will be as small as 100 x 100 nm. They will consume an even lower amount of energy (1 pW), possess computational prowess, as well as have multi-modal sensing, actuation, and energy harvesting capabilities, enabling them to perform intelligent tasks such as self-assembly, roaming, sleeping, and duty-cycling. These new classes of miniaturized Smart Dusts are called Electronic Particle (E-Particle).
Nanotechnology research has resulted in new materials and devices, such as silver nanoparticles and transistors that can be scaled down to up to 1 nm. Manufacturing and characterization tools such as atomic layer deposition, molecular-beam epitaxy, electron-beam lithography, focused ion beam, and atomic force microscopy, as well as new scaling technique such as Implosion or “shrinking” Fabrication will push forward further miniaturization and mass-production of nanomaterials and devices. Though still under research and development, this progress will revolutionize the future of Smart Dust and ubiquitous computing through e-particle. Transistors in a typical microprocessor will shrink down to 1 nm, while MEMS, fluidic, and optical microsystem scale will be reduced to around 10 nm by the end of the 21stcentury.
By the end of the 21stcentury, we will find e-particle spread out everywhere within and surrounding us. There are two types of e-particle: passive and active. Passive e-particles are in the order of magnitude smaller than active e-particles. The difference is that they do not have complex actuation capabilities to roam, fly, and self-assemble. Having less complexity allows passive e-particle to be much smaller than the active one. They are mostly used as sensing nodes and can be imagined as pollen grains. With the flaps, they can travel with the wind and in a stream, while sensing the environments. Active e-particles are bigger as they require larger power generator and more complex actuation platform, such as motorized wings, grips, or fins and stimulation techniques as such as drug-delivery, light emission, or charge injection. They have an ability to maneuver and self-assemble, shoal, or swarm into a bigger entity, similar to bees but in a much smaller scale, close to Phytoplankton.
In terms of e-particle sizes, active e-particle can be classified as PM 2.5, which is a fine particulate matter 2.5 micrometers or less in diameter or roughly 40 times less than a human hair diameter and the same size of a bacteria and animal cells. On the other hand, passive e-particle will go to a new class of PM 0.25 and have similar size to quantum dots, nanotubes, and viruses. Silk, organic, and inorganic silicon-based devices have been proven to be biodegradable and bioresorbable, however with various dissolving time response from seconds to days depending on the materials. Therefore, one can tune the lifespan of e-particles and even control it to self-destruct. Material choices and capabilities of these electronic particles that will be abundant in the air can, therefore, have impacts on the atmosphere and climate that could adversely affect human health through extreme inhalation or consumption. Similar to RFID or NFC, these particles can be encoded with specific address and can be linked to a large sensor network through a smartphone-like e-portal device, resulting in the unavoidable future of IoE and Big Data 2.0.
Transforming our world with Electronic Particle
Future of Sensing
Many miniaturized sensors can be spread around a large area to do fixed sensing on any geometry. The cost and scale complexity can be solved by adding autonomous mobility of these sensors. However, in some applications, active e-particles are power consuming and costly to deploy in large scale. There will be a more significant use of passive e-particles as “parasites”. They are able to selectively attach or embed themselves through the combination of magnetic attachment and van der Walls force to a mobile host. The e-particles will choose to attach or repel from the mobile host depending whether the host takes the particles closer to their objective or point of interest.
Just like the dispersed dandelion seeds or pollen grains, in the future thousands of passive e-particles can be spread around a smart micro-climate green-house through air vents or with smart drones for large-area monitoring of crops. Their miniaturized design with light-weight wings and petals allows them to fly freely mid-air to gain data of light intensity, soil temperature and humidity, as well as pH or nutrient levels and in a closed loop, control the climate of the green house. They can also be implanted into the plants through water diffusion through the roots, stem, or manual injection. These enable us to monitor the growth and health of the crops, and report us in real-time their quality when they are ready to be harvested. The passive e-particles will seamlessly dissolve in fluids as the crops are ready to be further distributed.
Ubiquitous sensing means that anyone can track any item at their home and have a digital inventory list of anything they own. All of the food in the shelf and refrigerator have e-particles that can be dissolved by using the e-portal device. Through a software platform, people can find any information about the expiry date, how was it produced, its supply chain, and real-time nutritional values.
in Crowd and City Sensing
Having around a hundred of passive e-particles in our clothing, another hundred roaming inside the body, and thousands floating in the air enable collection of large quantities of biometrics and environmental data. For example, some e-particles containing accelerometers can be used to monitor people movements and crowd, from indoor and outdoor pedestrian, inside a building, or in a large malls and festivals. These participatory, crowd sensing data and visualization can be used to predict future behavior of large-crowd for quick intervention. Microphones and GPS data can also be used to map noise pollution around the city, or as a canvas for acoustic sensing of an entire city to detect particular events around the city that would need immediate response.
in Ocean Monitoring
By feeding animals, such as fishes with the e-particles, we could monitor and track their movements and health. The data gathered will allow better understanding of migration timing, routes of travel, specific areas for breeding, and locations of high mortality. Through telemetry, we could also influence their behavior in decision making of what to eat and where to swim too. Enabling us to control what we eat eating. There are also e-particles spread around the ocean, flowing with the water stream, to give us access data to water and fluid velocity, temperature, pH, et cetera. Passive e-particles can choose to repel or self-dissolve upon contact with or in an alien host. Since the e-particles have abilities to choose their host, e-particles can be also deployed to spread evenly around a region in the ocean to form a distributed net of underwater sensor nodes with exact resolution.
in Safety and Military
E-particles will be widely used in the 22ndcentury for surveillance. Vision and acoustic sensing, active e-particles that are almost invisible and can swarm can be controlled to infiltrate buildings or camps. Even though mechanism such as electromagnetic interference can be used to disrupt these e-particles, their small size makes them so easy to embed and hide essentially in any object as well as to travel through the underground.
Future of Ecosystem
Biodigital is the new bio and the new digital. We will live in a bioelectronic ecosystem where every living thing will have e-particles travelling inside by inhalation or ingestion processes.
in Human-machine Interfaces
E-particles can travel to the brain through respiratory system and blood-air barrier, gas exchange. The e-particles could then further spread to olfactory bulb and tract, cerebral cortex, and spinal cord. By using external and subdural transceiver, these e-particles can act as neural dusts around the brain through piezo-actuation and electromagnetic field principles. These neural dusts will enable fine-grained, bi-directional brain-machine interface.
E-particles embedded in pills and water will allow ingestible systems that could deliver drugs through the gastrointestinal track. The dissolved pills or water will travel through the esophagus before it gets absorbed to the bloodstream. In the kidney, the water filters toxins out of the body, which gets transferred out through urine. The e-particles, while travelling through various parts and processes around the body, constantly sense physiological and biochemical markers and deliver drugs as appropriate.
in Plants and Animal
As we allow plants and animal to eat substances containing e-particles, we will be able to track their health condition and learn their behavior. Living fungi as an example, can sense and compute. Feeding them with e-particles will also enable us to influence its growth and properties by using electrostimulation or programmable drug injection. When the fungi die, the e-particles are still embedded within leaving a large electronic nervous system in a living or dead being. These e-particles can still do environmental sensing or choose to dissolve within their hosts.
Future of Materials
The nanoscale, subatomic level of these e-particles enables us to rethink about materials that compute. By mixing water with e-particles, all future plants will have e-particles embedded within their leaf, stem, roots, flowers, and fruits. All of the wood will have electronics embedded within. People can design their own smart objects by incorporating e-particles to silicone mold, yarns, paper, cement, and more.
in Interior Design
Since any type of wood from cedar, walnut, oak, to plywood will be embedded with e-particles, any type of furniture from in our house and office will become smarter and will be able to detect presence and our interaction on or to it. By actuating the embedded e-particles, we can engineer plants growth, enabling us to shape trees into furniture. Mixing cement with e-particles for smart concrete also enables every wall in the future to be a large interactive surface for various applications from gesture sensing, heating, to activity recognition.
Passive e-particles will also be incorporated in fiber drawing and textile manufacturing. Future fabrics are multi-functional and can change colors, monitor health, and actuate scents simultaneously. Various passive e-particles in a spray-on fabric can be used to make smart clothing on the go. Active e-particles can work with biological entities (such as spiders or silkworms) to pattern, weave, or knit on-body in real-time.
E-particles are particularly gaining customer interests through smart skincare. Future lotion will have e-particle beads embedded that speed up skin treatment processes. With ultrasound-enabled e-particles, nutrients or drugs can be delivered and diffuse to the skin in a much faster rate. E-particle in the form of moisturizers or sunscreen can work adaptively as the environment changes. Perfumes made out of scent infused e-particles can release different odors based on the physiological and physical activity context of the customer.
Future of Programmable Matters
in Intelligent Architecture and Building Technology
Active e-particles could self-assemble by attaching to each other magnetically and climbing on top of another to create smart, deployable, 3D structures, from objects to furniture to buildings. This is particularly useful for extreme environments and space applications, where these e-particles can be packed in a compact manner before getting controlled to form building blocks.Some active e-particles have motorized wings and can swarm together. Each particle can actuate a single pixel RGB color. Having million of these active e-particles in mid-air will enable static, floating 3D display.
in Self-Reconfigurable Robotics
Having access to active e-particles will also enable some people to have physical companion that can change into any form and function depending on the user’s choice and context. From pets, to tablets, to tools. For example, as the user walks around the park, the e-particles will assemble into the user’s favorite pet, upon a notification, the e-particles could fly and transform into a floating screen in front of the user. In the office, the e-particles could transform into a laptop, while in the kitchen, they transform into knife, cutting board, spoon, fork, and plates. The possibility is limitless.
Environmental and Societal Impact
Electronic Pollution and Risk Prevention
Mass-manufacturing of these e-particles mean that they will become abundant throughout the 22ndcentury, making them as dense and as common as silts and dusts. They, therefore, significantly give an environmental impact. The government prohibits the development of e-particles with carcinogenic materials, that could penetrate into lungs and diffuse to the blood streams and can cause premature deaths from heart attacks and respiratory disease. It will be common for transportation, house, and residences to have several e-particles filters and only the higher-income family can afford transforming their entire house and their pods to a class 10, cleanroom grade. This type of house and transportation will have high efficiency particulate air filtering system that constantly circulates the air with laminar flow and remove particulates simultaneously. In addition, due to their high complexity and cost, only 5% of the entire population of the earth will own active e-particles and only several companies develop them, while passive e-particles will be abundant and produced in all industries. Companies that are producing e-particles are closely monitored by the government to avoid the gray goo effect, in which nanomachines get out of control by converting all organic matter to replicate themselves.
Tracking, Disposal, and Dialysis
The e-portal is a device that can track and actuate dissolution of surrounding e-particles. Another approach to dispose e-particles is to bury them under the ground or submerging them to the water. Typical dissolution time is 3 days to 1 week for passive e-particle and around 5 weeks to 3 months for active e-particles, with faster rate when exposed to high temperature. Wearable dialysis device provided by medical centers can be used to remove e-particles from the bloodstream.
Some people who are skeptical and doubtful of living with e-particles will create their own electronic mask that cover both nose and mouth, to avoid inhaling and ingesting these particles. They will also live in a place with a high-intensity electromagnetic field source on the walls to disrupt the e-particles network. They are afraid of the possibilities of surveillance from the government or other private sector entities. They are worried that the e-particles working as neural dusts in their central and peripheral nervous system will be used to read their mind or even worst, control their behavior at any point in time.