2026-03-31 02:00:02
To stay competitive, many small businesses need advanced wireless communication networks, not only to communicate but also to leverage technologies such as artificial intelligence, the Internet of Things, and robotics. Often, however, the businesses lack the technical expertise needed to install, configure, and maintain the systems.
Bhaskara Rallabandi, who spent more than two decades working for major telecom companies, decided to use his expertise to help small businesses. Rallabandi, an IEEE senior member, is an expert certified by the International Council on Systems Engineering.
Cofounder
Bhaskara Rallabandi
Founded
2023
Headquarters
Frisco, Texas
Employees
100
In 2023 he helped found Invences, a telecommunications automation company headquartered in Frisco, Texas.
Invences services include designing, building, and installing data centers, as well as cost-effective and secure wireless, private, IoT, and virtual communications networks.
The company has set up systems for farms, factories, and universities in rural and urban areas including underserved communities. Its mission, Rallabandi says, is to “build autonomous, ethical, and sustainable networks that connect communities intelligently.”
For his work, he was recognized last year for “entrepreneurial leadership in founding and scaling a U.S.-based technology company, advancing innovation in 5G/6G and Open RAN [radio access network], shaping global standards, and inspiring future leaders through mentorship and community impact” with the IEEE-USA Entrepreneur Achievement Award for Leadership in Entrepreneurial Spirit.
He began his telecommunications career in 2009 as a manager and principal network engineer at Verizon’s Innovation Labs in Waltham, Mass. He and his team ran some of the earliest long-term evolution and evolved packet core performance trials. (LTE is the 4G wireless broadband standard for mobile devices. EPC is the IP-based, high-performance core network architecture for 4G LTE networks.)
That work at Innovation Labs, he says, was key to the development of the first 4G systems. It set the stage for scalable, interoperable broadband architectures that underpin today’s 5G and 6G designs.
“We built the first bridge between legacy and cloud-native networks,” he says.
He left in 2011 to join AT&T Labs in Redmond, Wash. As senior manager and principal solutions architect, he oversaw the design, integration, and testing of the company’s next-generation wireless systems. He also led projects that redefined automation of networks and set up cloud computing systems including FirstNet, the nationwide broadband network for first responders, and VoLTE, the first voice-over-video LTE for conducting video calls.
In 2018 Rallabandi was hired as a principal and a senior manager of engineering at Samsung Networks Division’s Technology Solutions Division, in Plano, Texas. He led the development of 5G virtualization and Open RAN initiatives, which enable more flexible, scalable, and efficient large network deployments and interoperability among vendors.
Feeling that he wasn’t reaching his full potential in the corporate world, and to help small businesses, he opted to start his own venture in 2023 with his wife, Lakshmi Rallabandi, a computer science engineer. She is Invences’s CEO, and he is its founding principal and chief technology advisor.
Invences, which is self-funded and employs about 100 people, has more than 50 customers from around the world.
“I wanted to do something more interesting where I could use the knowledge I gained working for these big companies to fill the gaps they overlooked in terms of automation” for small businesses, he says. “I have a team of people who, combined, have 200 years of technology experience.”
The startup builds networks that simplify its clients’ operations and reduce their costs, he says.
Instead of duplicating how major telecom carriers build networks for dense urban areas, he says, his designs reimagine the network architecture to lower its complexity, costs, and operational overhead.
“Connectivity should not be a luxury. Rural communities deserve an infrastructure that fits their needs.”
The systems integrate new technologies such as Open RAN, virtualized RAN, digital twins, telemetry, and advanced analytics. Some networks also incorporate agentic AI, an autonomous system that runs independently of humans and uses AI agents that plan and act across the network. Digital twins evaluate the agent’s decisions before releasing them.
“Autonomy is not about removing humans from the loop,” Rallabandi says. “It is about giving systems the ability to manage complexity so humans can focus on intent and outcomes.”
Rallabandi also has worked on AI-driven telecom observability technologies designed to allow networks to detect anomalies and optimize performance automatically.
He has developed a virtual O-RAN innovation lab, where clients can test the interoperability of their 5G systems, try out their enhancements, run trials of future functions, and experiment with updates.
Invences partnered with Trilogy Networks to build the FarmGrid platform for farms in Fargo, N.D., and Yuma, Ariz. FarmGrid used private 5G networks, edge-computing AI, and digital twins to make the operations more efficient.
“The project connects farms with sensors, analytics platforms, and autonomous equipment to enable precision agriculture, water optimization, and real-time decision-making,” Rallabandi says.
IEEE Senior Member Bhaskara Rallabandi talks about partnering with Trilogy Networks to build the FarmGrid platform for farms in Fargo, N.D., and Yuma, Ariz.TECKNEXUS
Rallabandi says he believes staying involved with IEEE is important to his career development and a way to give back to the profession. He is a frequent invited speaker at IEEE conferences.
He is active with IEEE Future Networks and its Connecting the Unconnected (CTU) initiative. Members of the Future Networks technical community work to develop, standardize, and deploy 5G and 6G networks as well as successive generations.
CTU aims to bridge the digital divide by bringing Internet service to underserved communities. During itsannual challenge, Rallabandi works with the winning students, researchers, and innovators to help them turn their concepts into affordable, cost-effective options.
“CTU represents the best of IEEE,” he says. “It is about taking innovation out of conferences and into communities that need it the most.
“Connectivity should not be a luxury. Rural communities deserve an infrastructure that fits their needs.”
He participates in the recently launched IEEE Future Networks Empowerment Through Mentorship initiative, which helps innovators, entrepreneurs, and startups expand their companies by educating them about finance, marketing, and related concepts.
“IEEE gives me both a voice and a responsibility,” Rallabandi says. “We’re not just developing technology; we are shaping how humanity connects.”
2026-03-30 21:00:02
Facial recognition technology (FRT) dates back 60 years. Just over a decade ago, deep-learning methods tipped the technology into more useful—and menacing—territory. Now, retailers, your neighbors, and law enforcement are all storing your face and building up a fragmentary photo album of your life.
Yet the story those photos can tell inevitably has errors. FRT makers, like those of any diagnostic technology, must balance two types of errors: false positives and false negatives. There are three possible outcomes.
a) identifies the suspect, since the two images are of the same person, according to the software. Success!
b) matches another person in the footage with the suspect’s probe image. A false positive, coupled with sloppy verification, could put the wrong person behind bars and lets the real criminal escape justice.
c) fails to find a match at all. The suspect may be evading cameras, but if cameras just have low-light or bad-angle images, this creates a false negative. This type of error might let a suspect off and raise the cost of the manhunt.
In best-case scenarios—such as comparing someone’s passport photo to a photo taken by a border agent—false-negative rates are around two in 1,000 and false positives are less than one in 1 million.
In the rare event you’re one of those false negatives, a border agent might ask you to show your passport and take a second look at your face. But as people ask more of the technology, more ambitious applications could lead to more catastrophic errors. Let’s say that police are searching for a suspect, and they’re comparing an image taken with a security camera with a previous “mug shot” of the suspect.
Training-data composition, differences in how sensors detect faces, and intrinsic differences between groups, such as age, all affect an algorithm’s performance. The United Kingdom estimated that its FRT exposed some groups, such as women and darker-skinned people, to risks of misidentification as high as two orders of magnitude greater than it did to others.
Less clear photographs are harder for FRT to process.iStock
What happens with photos of people who aren’t cooperating, or vendors that train algorithms on biased datasets, or field agents who demand a swift match from a huge dataset? Here, things get murky.
THE NEGATIVES OF FALSE POSITIVES
2020: Robert Williams’s wrongful arrest cost him detention. The ensuing settlement requires Detroit police to enact policies that recognize FRT’s limits. iStock
ALGORITHMIC BIAS
2023: Court bans Rite Aid from using facial recognition for five years over its use of a racially biased algorithm. iStock
TOO FAST, TOO FURIOUS?
2026: U.S. immigration agents misidentify a woman they’d detained as two different women. VICTOR J. BLUE/BLOOMBERG/GETTY IMAGES
Consider a busy trade fair using FRT to check attendees against a database, or gallery, of images of the 10,000 registrants, for example. Even at 99.9 percent accuracy you’ll get about a dozen false positives or negatives, which may be worth the trade-off to the fair organizers. But if police start using something like that across a city of 1 million people, the number of potential victims of mistaken identity rises, as do the stakes.
What if we ask FRT to tell us if the government has ever recorded and stored an image of a given person? That’s what U.S. Immigration and Customs Enforcement agents have done since June 2025, using the Mobile Fortify app. The agency conducted more than 100,000 FRT searches in the first six months. The size of the potential gallery is at least 1.2 billion images.
At that size, assuming even best-case images, the system is likely to return around 1 million false matches, but at a rate at least 10 times as high for darker-skinned people, depending on the subgroup.
Responsible use of this powerful technology would involve independent identity checks, multiple sources of data, and a clear understanding of the error thresholds, says computer scientist Erik Learned-Miller of the University of Massachusetts Amherst: “The care we take in deploying such systems should be proportional to the stakes.”
2026-03-28 03:05:59
In a landmark case, a jury found this week that Meta and YouTube negligently designed their platforms and harmed the plaintiff, a 20-year-old woman referred to as Kaley G.M. The jury agreed with the plaintiff that social media is addictive and harmful and was deliberately designed to be that way. This finding aligns with my view as a clinical psychologist: that social media addiction is not a failure of users, but a feature of the platforms themselves. I believe that accountability must extend beyond individuals to the systems and incentives that shape their behavior.
In my clinical practice, I regularly see patients struggling with compulsive social media use. Many describe a pattern of “doomscrolling,” often using social media to numb themselves after a long day. Afterwards, they feel guilty and stressed about the time lost yet have had limited success changing this pattern on their own.
It’s easy to understand why scrolling can be so addictive. Social media interfaces are built around a powerful behavioral mechanism known as intermittent reinforcement, says Judson Brewer, an addiction researcher at Brown University, which is the strongest and most effective type of reinforcement learning. This is the same mechanism that slot machines rely on: Users never know when the next reward—a shower of quarters, or a slew of likes and comments—will appear. Not all the videos in our feeds captivate us, but if we scroll long enough, we are bound to arrive at one that does. The ongoing search for rewards ensnares us and reinforces itself.
Individuals typically struggle on their own to address compulsive social media use. This should be no surprise, as habits are not typically broken through sheer discipline but rather by altering the reinforcement loops that sustain them. Brewer argues that “there’s actually no neuroscientific evidence for the presence of willpower.” Placing the burden to self-regulate solely on users misses the deeper issue: These platforms are engineered to override individual control.
A growing body of research identifies social media use and constant digital connectivity as important influences on the growing incidence of adolescent mental health problems. Brewer notes that adolescents are particularly vulnerable, as they are in a “developmental phase” in which reinforcement learning processes are especially strong. This vulnerability can be exploited by the design features of large social media platforms.
NPR uncovered records from a recent lawsuit filed by Kentucky’s attorney general against TikTok. According to these documents, TikTok implemented interface mechanisms such as autoplay, infinite scrolling, and a highly personalized recommendation algorithm that were systematically optimized to maximize user engagement.
TikTok’s algorithmically tailored “For You” content continuously tracks user behaviors, such as how long a video is watched, whether it is replayed, or quickly skipped. The feed then curates short videos, or reels, for the user based on past scrolling behavior and what is most likely to hold attention.
These documents show one example of a tech company knowingly designing products to maximize attention. I believe social media companies also have the capacity to reduce addictiveness through intentional design choices.
The good news is we are not helpless. There are multiple levers for change: how we collectively talk about social media, how our governments regulate its design and access, and how we hold companies accountable for practices that shape user behavior.
Some countries are moving quickly to set policy around social media use. Australia has imposed a minimum age of 16 for social media accounts, with similar bans pending in Denmark, France, and Malaysia.
These bans typically rely on age verification. Users without verified accounts can still passively watch videos on platforms like YouTube, but this approach removes many of the most addictive features, including infinite scroll, personalized feeds, notifications, and systems for followers and likes. At the same time, age verification may cause different problems in the online ecosystem.
Other countries are targeting social media use in specific contexts. South Korea, for example, banned smartphone use in classrooms. And the United Kingdom is taking a different approach; its Age Appropriate Design Code instructs platforms to prioritize children’s safety while designing products. The code includes strong privacy defaults, limits on data collection, and constraints on features that nudge users toward greater engagement.
A report called Breaking the Algorithm, from Mental Health America, argues that social media platforms should shift from maximizing engagement to supporting well-being. It calls for revamping recommendation systems to spot patterns of unhealthy use and adjusting feeds accordingly—for example, by limiting extreme or distressing content.
The report also argues that users should not have to intentionally opt out of harmful design features. Instead, the safest settings should be the default. The report supports regulatory measures aimed at limiting features such as autoplay and infinite scroll while enforcing privacy and safety settings.
Platforms could also give users more control by adding natural speed bumps, such as stopping points or break reminders during scrolling. Research shows that interrupting infinite scroll with prompts such as “Do you want to keep going?” substantially reduces mindless scrolling and improves memory of content.
Some social media platforms are already experimenting with more ethical engagement. Mastodon, an open-source, decentralized platform, displays posts chronologically rather than ranking them for engagement, and does not offer algorithmically generated feeds like “For You.” Bluesky gives users control by letting them customize their own algorithms and toggle between different feed types, such as chronological or topic-based filters.
In light of the recent verdict, it is time for a national conversation about accountability for social media companies. Individual responsibility will always be important, but so are the mechanisms employed by big tech to shape user behavior. If social media platforms are currently designed to capture attention, they can also be designed to give some of it back.
2026-03-28 02:00:04
In today’s technological landscape, the only constant is the rate of obsolescence. As engineers move deeper into the eras of 6G, ubiquitous artificial intelligence, and hyper-miniaturized electronics, a traditional degree is only a starting point.
To remain competitive in today’s job market, technical specialists must evolve into future-ready professionals by cultivating more than just niche expertise. Success now demands a high degree of adaptive intelligence and strategic communication, allowing specialists to translate complex data into actionable business decisions as industry shifts accelerate.
To bridge the gap between technical proficiency and organizational leadership, the IEEE Professional Development Suite offers training on programs designed to build the strategic competencies required to navigate today’s complex landscape. The suite provides deep technical dives into domains such as telecommunications connectivity and microelectronics reliability. Organizations can stay ahead of the curve through informed decision-making and a future-ready workforce.
Within the semiconductor sector, which is projected to become a US $1 billion industry by 2030, electrostatic discharge (ESD) is a major reliability challenge. Because even a microscopic, unnoticed discharge can compromise a semiconductor, ESD issues account for up to one-third of all field failures, according to the EOS/ESD Association.
IEEE’s targeted training—the online Practical ESD Protection Design certificate program—equips teams with technical protocols to mitigate the risks and ensure long-term hardware reliability. Specialized ESD training has become essential for chip designers and manufacturing professionals seeking to improve discharge control.
The interactive modules cover theory, real-world case studies, and practical mitigation techniques. The standards-based instruction is aligned with ANSI/ESD S20.20–21: Protection of Electrical and Electronic Parts and other industry guidelines.
As 5G network capabilities expand globally, so does the demand for engineers who can master the protocols and procedures required to manage complex telecommunications systems. The IEEE 5G/6G Essential Protocols and Procedures Training and Innovation Testbed, in partnership with Wray Castle, takes a deep dive into the 5G network function framework, registration processes, and packet data unit session establishment. The program is designed for system engineers, integrators, and technical professionals responsible for 5G signaling. Stakeholders such as network operators, equipment vendors, regulators, and handset manufacturers could find the program to be beneficial as well.
“The IEEE Professional Development Suite ensures that learners are not just keeping pace with change but helping to drive it.”
To bridge the gap between theory and practice, the course includes three months of free access to the IEEE 5G/6G Innovation Testbed. The secure, cloud-based platform offers a private, end-to-end 5G network environment where individuals and teams can gain hands-on experience with critical system signaling and troubleshooting.
Technical knowledge alone is not enough to climb the corporate ladder. To thrive today, engineering leaders must have a strategic vision and people-centric leadership skills.
The IEEE Leading Technical Teams training program focuses on the challenges of managing engineers in R&D environments and fostering creative problem-solving through an immersive learning experience. It’s designed for professionals who have been in a leadership position for at least six months. Participants can gain self-awareness.
The program includes a 360-degree assessment that gathers feedback about the individual from peers and direct reports to build a personalized development plan. The goal is to help technical professionals transition from high-performing individual contributors into leaders who drive innovation by inspiring their teams rather than just managing tasks.
Organizations can enroll groups of 10 or more to learn as a cohort—which can ensure that everyone stays on the same page while setting a training schedule that fits the team’s deadlines.
In collaboration with the Rutgers Business School, IEEE offers two mini MBA programs to bridge the gap between technical expertise and executive leadership. The programs offer flexibility to fit the demanding schedules of senior professionals. The online format lets participants engage with content as their time permits, while live virtual office hours with faculty provide opportunities for real-time interaction.
During the mini MBA for engineers 12-week curriculum, technical professionals master core competencies such as financial analysis, business strategy, and negotiation to effectively transition into management roles.
The mini MBA in artificial intelligence embeds AI literacy directly into business strategy rather than treating the technology as a standalone subject. Participants learn to evaluate AI through financial modeling and governance frameworks, gaining a practical foundation to lead initiatives that incorporate the technology.
The programs are offered to individuals as well as to organizations interested in training groups of 10 employees or more.
All the programs within the IEEE Professional Development Suite offer continuing education units and professional development hours.
Earning globally recognized credits provides a professional advantage, signaling a commitment to growth that often serves as a prerequisite for advancing into senior, lead, or principal roles. Additionally, the credits satisfy annual professional engineering license renewal requirements, ensuring practitioners remain compliant while expanding their capabilities.
Developed by IEEE Educational Activities, the training programs are peer-reviewed and built to align with industry needs. By focusing on upskilling (improving current skills) and reskilling (learning new ones), the IEEE Professional Development Suite ensures that learners are not just keeping pace with change but helping to drive it.
2026-03-28 00:30:03
Video Friday is your weekly selection of awesome robotics videos, collected by your friends at IEEE Spectrum robotics. We also post a weekly calendar of upcoming robotics events for the next few months. Please send us your events for inclusion.
Enjoy today’s videos!
“Roadrunner” is a new bipedal wheeled robot prototype designed for multimodal locomotion. It weighs around 15 kg (33 lb) and can seamlessly switch between its side-by-side and in-line wheel modes and stepping configurations depending on what is required for navigating its environment. The robot’s legs are entirely symmetric, allowing it to point its knees forward or backward, which can be used to avoid obstacles or manage specific movements. A single control policy was trained to handle both side-by-side and in-line driving. Several behaviors, including standing up from various ground configurations and balancing on one wheel, were successfully deployed zero-shot on the hardware.
Incredibly (INCREDIBLY!) NASA says that this is actually happening.
NASA’s SkyFall mission will build on the success of the Ingenuity Mars helicopter, which achieved the first powered, controlled flight on another planet. Using a daring midair deployment, SkyFall will deliver a team of next-gen Mars helicopters to scout human landing sites and map subsurface water ice.
[ NASA ]
NASA’s MoonFall mission will blaze a path for future Artemis missions by sending four highly mobile drones to survey the lunar surface around the Moon’s South Pole ahead of astronauts’ arrival there. MoonFall is built on the legacy of NASA’s Ingenuity Mars Helicopter. The drones will be launched together and released during descent to the surface. They will land and operate independently over the course of a lunar day (14 Earth days) and will be able to explore hard-to-reach areas, including permanently shadowed regions (PSRs), surveying terrain with high-definition optical cameras and other potential instruments.
For what it’s worth, Moon landings have a success rate well under 50%. So let’s send some robots there to land over and over!
[ NASA ]
In Science Robotics, researchers from the Tangible Media group led by Professor Hiroshi Ishii, together with colleagues from Politecnico di Bari, present Electrofluidic Fiber Muscles: a new class of artificial muscle fibers for robots and wearables. Unlike the rigid servo motors used in most robots, these fiber-shaped muscles are soft and flexible. They combine electrohydrodynamic (EHD) fiber pumps—slender tubes that move liquid using electric fields to generate pressure silently, with no moving parts—with fluid-filled fiber actuators. These artificial muscles could enable more agile untethered robots, as well as wearable assistive systems with compact actuation integrated directly into textiles.
[ MIT Media Lab ]
In this study, we developed MEVIUS2, an open-source quadruped robot. It is comparable in size to the Boston Dynamics Spot, equipped with two lidars and a C1 camera, and can freely climb stairs and steep slopes! All hardware, software, and learning environments are released as open source.
[ MEVIUS2 ]
Thanks, Kento!
What goes into preparing for a live performance? Arun highlights the reliability testing that goes into trying a new behavior for Spot.
[ Boston Dynamics ]
In this work, a multirobot planning and control framework is presented and demonstrated with a team of 40 indoor robots, including both ground and aerial robots.
That soundtrack, though.
[ GitHub ]
Thanks, Keisuke!
Quadrupedal robots can navigate cluttered environments like their animal counterparts, but their floating-base configuration makes them vulnerable to real-world uncertainties. Controllers that rely only on proprioception (body sensing) must physically collide with obstacles to detect them. Those that add exteroception (vision) need precisely modeled terrain maps that are hard to maintain in the wild. DreamWaQ++ bridges this gap by fusing both modalities through a resilient multimodal reinforcement learning framework. The result: a single controller that handles rough terrains, steep slopes, and high-rise stairs—while gracefully recovering from sensor failures and situations it has never seen before.
That cliff behavior is slightly uncanny.
[ DreamWaQ++ ]
I take issue with this from iRobot:
While the pyramid exploration that iRobot did was very cool, they did it with a custom-made robot designed for a very specific environment. Cleaning your floors is way, way harder. Here’s a bit more detail on the pyramids thing:
[ iRobot ]
More robots in the circus, please!
[ Daniel Simu ]
MIT engineers have designed a wristband that lets wearers control a robotic hand with their own movements. By moving their hands and fingers, users can direct a robot to perform specific tasks, or they can manipulate objects in a virtual environment with high-dexterity control.
[ MIT ]
At Nvidia GTC 2026, we showcased how AI is moving into the physical world. Visitors interacted with robots using voice commands, watching them interpret intent and act in real time—powered by our KinetIQ AI brain.
[ Humanoid ]
Props to Sony for its continued support and updates for Aibo!
[ Aibo ]
This robot looks like it could be a little curvier than normal?
[ LimX Dynamics ]
Developed by Zhejiang Humanoid Robot Innovation Center Co., Ltd., the Naviai Robot is an intelligent cooking device. It can autonomously process ingredients, perform cooking tasks with high accuracy, adjust smart kitchen equipment in real time, and complete postcooking cleaning. Equipped with multimodal perception technology, it adapts to daily kitchen environments and ensures safe and stable operation.
That 7x is doing some heavy lifting.
[ Zhejiang Lab ]
This CMU RI Seminar is by Hadas Kress-Gazit from Cornell, on “Formal Methods for Robotics in the Age of Big Data.”
Formal methods—mathematical techniques for describing systems, capturing requirements, and providing guarantees—have been used to synthesize robot control from high-level specification, and to verify robot behavior. Given the recent advances in robot learning and data-driven models, what role can, and should, formal methods play in advancing robotics? In this talk I will give a few examples for what we can do with formal methods, discuss their promise and challenges, and describe the synergies I see with data-driven approaches.
2026-03-27 22:41:42
We’re all familiar with mixing red, yellow, and blue paint in various ratios to instantly make all kinds of colors. This works great for oils or watercolors, but fails when it comes to cans of spray paint. The paint droplets can’t be blended once they are aerosolized. Consequently, although spray cans are great for applying even coats of paint to large areas very quickly, spray-paint artists need a separate can for every color they want to use—until now.
Back in 2018, when I first saw professional spray artists lugging dozens to hundreds of cans to their work sites, I was inspired to start noodling on a solution. I’ve worked at Google X, Alphabet’s “moonshot factory,” as a hardware engineer, and I’m now building a startup in mechanical-design software. I’m no painter, but I know my way around mechatronics.
I wanted my solution to be inexpensive and simple enough to build as a DIY project and functional enough for an artist to use, without breaking their flow. So I began prototyping a system that combines base colors while they are still in pressurized form from off-the-shelf cans.
This new rotary pinch valve can be opened and closed in tens of milliseconds and prevents backpressure from clogging lines.James Provost
I tried a few approaches where pres-surized paint from the base-color cansfed through tubes into a mixing channel, before emerging from a spray head. To control the ratios, I decided to borrow a trick that would be familiar to anyone who’s ever had to control the bright-ness of an LED using a microcontroller: pulse-width modulation. Initially, I used electronically controlled solenoid valves to release the paint from the cans. The paint would flow into a mixing channel for a relative duration that corresponded to the ratio of the base colors required to make a given hue. However, this failed because different cans never have the same internal pressure. Whenever two valves were open at the same time, the pressure difference would make paint flow backward into the lower-pressure can.
As an alternative, I removed the mixing channel and tried making the paint pulses from each can sequentially converge into a tube so that no more than one valve would ever be open at a time. Surprisingly, this worked perfectly. The backflow was eliminated, and it turned out that the natural turbulence of the flow was sufficient to mix the paints. Let’s say you want to produce a clementine orange color. This requires yellow and red paint in a ratio of 1:2, so the yellow valve opens for a period of time, and then the red valve opens for twice as long. The system then keeps repeating this cycle of pulses in a rapid pace to instantly create the spray-paint color you want.
The theory is straightforward, but making this work in practice took quite a bit of experimentation. First, I had to determine the actual durations of pulses that would produce evenly mixed colors, not just their ratios. I also needed to work out the size of the tubing (too narrow and you’d get low spray force; too wide and you’d have paint accumulating in the tubes). Eventually I settled on a maximum pulse duration of 250 milliseconds and a tube diameter of 1 millimeter.
Even though the system worked, the solenoid valves I used constantly clogged up. Designed for water purifiers, the valves didn’t prevent paint from entering the mechanism, where the paint would harden. Moreover, when the valves were turned off, they could stop backflow only if the inlet remained pressurized. So disconnecting a paint can from the system would cause instant leaking. Other off-the-shelf valves I tried couldn’t cycle fast enough and were too expensive.
I had some spectacular failures along the way of the sort that only pressurized paint can provide.
So I created my own mechanism: a high-speed, electronically controlled, rotary pinch valve. It has a stepper motor that rotates a lever with a rolling bearing to constrict fluid flow inside a flexible tube. This concept isn’t new—there’s something like them in every peristaltic pump. But I added a spring to firmly hold the lever in the closed position against any back pressure when the motor isn’t powered, making it a normally closed valve that isolates the attached can. Additionally, the valve is fast enough to be open for as little as 30 milliseconds.
I went through four major prototypes of the system before reaching a working version, and I had some spectacular failures along the way of the sort that only pressurized paint can provide. The final version uses four base colors—red, yellow, blue, and white—with the color mix controlled by four knobs attached to an Arduino Nano and a small display. The flow of paint is triggered by a push button placed above the spray head, similar to a spray can’s nozzle.
Cans holding base colors (A) are attached to valves (B). An Arduino-based control panel (C) opens and closes valves to mix paint before it is aerosolized (E). By quickly opening and closing valves with varying durations in sequence (D), you can mix paint in specific ratios to create desired colors.James Provost
The length of time a base color’s paint valve can be open is one of eight values between 30 and 250 ms. This means that the entire system—which I coincidentally dubbed Spectrum—can create hundreds of distinct spray-paint colors instantly. It produces less than 84 (or 4,096) colors because duration ratios that are a multiple of each other will produce the same color—for example, 2:3 and 4:6. I added a force sensor to the push button, which allows for a gradient: Two color mixes can be dialed in, and as I increase my thumb’s pressure on the button, the paint mix shifts from one color to the other.
Spectrum’s various fixtures are 3D-printed, and project files and videos are available through my website at https://www.sandeshmanik.com/projects/spectrum. Preprints of technical descriptions of the rotary pinch valve and mixing methodology are available on TechRxiv. The total cost for the bill of materials is less than US $150.
Working on and off on the side for about seven years, I finally finished developing my system and writing the documentation in late 2025. After I posted a video to social media, I was heartened by the immediate positive response from spray-paint artists around the world. I’m now creating step-by-step instructions so that nontechnical people can build their own Spectrum paint sprayer. I look forward to seeing what creations artists out in the wild make!