Today's interview is with Sissi Liu , CEO & Co-Founder, Metalmark Innovations.
What Is Metalmark?
What Is Metalmark, And Can You Share More About Your Mission?
Sissi Liu - Metalmark spun out of Harvard in 2018. We are organized as a public benefit corporation (PBC) with a mission to make a positive impact on human and environmental well-being by leveraging bioinspired material science. Our current focus is solving problems at the intersection of climate change and health, starting with indoor environmental quality.
Improving Indoor Air Quality
How Do Metalmark's Air Cleaning Products Improve Indoor Air Quality In The Context Of Climate-Related Events Like Wildfires?
Sissi Liu - We developed the Tatama™, the self-renewing air cleaning solution whose baseline technology was rigorously tested and awarded for its ability to safely and effectively capture harmful smoke particles by the US EPA’s Cleaner Indoor Air during Wildfires Challenge. Uniquely, the combination of our patented technology and proprietary material significantly extends the filter lifetime by up to 10X when compared with those of typical HEPA air purifiers. The system is designed for commercial building applications (e.g., hospitals, schools, offices, etc.) to maximize the efficiency of air cleaning and energy. This is the subject of a recently published paper: The Crucial Role of Ventilation Effectiveness in Air Cleaning. With the onboard sensors and cloud management, system operations can help balance occupant health and energy efficiency requirements at the campus and building levels. Finally, our apps track and analyze indoor air quality patterns to help customers understand the benefits of their investments.
Recently, we also introduced the Sierra™ Smoke Safe filter, which is the only HVAC filter (rated MERV 13) tested to deliver high efficacy for wildfire smoke removal with low energy use benefits.
Inspiration
Metalmark's Technology Is Inspired By Nature. Can You Explain How This Biomimicry Approach Enhances The Effectiveness Of Your Air Purification Systems?
Sissi Liu - Nature has provided inspiration to scientists and inventors for millennia. When dealing with complex problems like air quality, we turned to nature for ideas. Natural organisms have spent millions of years refining solutions to complex problems and adapting to challenging environments through an unparalleled "R&D" process. One of its key strategies is introducing multifunctionality through creating structural features at the nano and micro length scales, where materials and structures serve multiple purposes simultaneously. These natural systems are incredibly efficient, addressing various challenges in the most resourceful ways, resulting in highly functional and elegant designs. What's incredible is that the resulting materials are also safe for the ecosystems, recyclable, and renewable. Our technology is built on the same principles. The groundbreaking materials innovation was initially inspired by the nanostructures found in the scales of metalmark butterfly’s wings. Our proprietary coating provides both sorption and catalytic functions, working together to trap and break down pollutants. Paired with our patented Tatama system, this coating enables effective filter self-renewal by breaking down trapped contaminants. The same advanced coating also enhances wildfire smoke filtration in our SierraTM Smoke Safe Filter, delivering cleaner, safer air.
Unique Technology
Wildfire Smoke Poses Unique Challenges Due To Its Tiny Particle Size, Which Traditional Filters Can’t Handle Over Time. How Does Metalmark’s Technology Rise To This Challenge?
Sissi Liu - You're correct to observe that smoke particles are tiny. What most people don't realize is just how tiny they are. Its categorization as PM2.5 suggests that, like many other PM of concern, smoke particles are also close to 2.5 microns in diameter. It turns out that smoke particles are an order of magnitude smaller; they average around 0.1-0.3 microns (100-300 nm). Particles below 0.3 microns can penetrate the lungs and enter the bloodstream. Stanford researchers warn that wildfire smoke can be 10x as toxic as other air pollutants. Meanwhile, other recent research highlights that smoke is associated with increased cardiopulmonary diseases, spontaneous premature births, and, in the long run, significantly higher dementia risks.
Another problem is that smoke can spread to areas thousands of miles away and linger in the air far longer after fire containment. The situation is made worse with more hazardous toxins (such as those that result from urban fires), which can hitch a ride on tiny smoke particles and infiltrate indoors. Recent studies show that smoke from far away increases health risks. This is consistent with estimates showing that the smoke is responsible for 8,000-30,000 premature deaths/year in the US, compared with ~10s direct wildfire deaths. That's a ~1,000-fold difference.
The current recommendations for smoke protection include: 1) staying indoors; 2) using MERV 13 or better HVAC filters; 3) operating HEPA + sorbent air purifiers; 4) wearing N95 masks + sorbent respirators when outdoors.
In terms of filters, it turns out that smoke's aerosol composition makes it stick and accumulate on filters differently from salt particles typically used for filter testing. The bottom line is that a) most MERV 13 and even many HEPA filters are made with materials that are ineffective for wildfire smoke filtration or they decay within hours of usage; b) a filter MERV rating does not provide information that translates to filter effectiveness for wildfire smoke removal for a large portion of commercial filters. Our published research can be found here.
We developed the Sierra filter by coating our proprietary material on commercial filter material to achieve higher filtration efficiency of smoke particles while maintaining other filtration benefits and low pressure–a key requirement for many HVAC equipment and from an energy consumption perspective.
Our Tatama air cleaner, on the other hand, provides high smoke filtration efficiency. The self-renewal technology enables longer-term protection with far fewer filter replacement headaches and landfill waste generation.
Tackling Pandemic Risk
As Urban Centers Grow Denser And Biodiversity Shrinks, We’re Facing A Rise In Pathogens and Pandemic Risks. How Does Metalmark See Air Purification As A Key Solution To These Interconnected Challenges?
Sissi Liu - An important yet often overlooked aspect of the COVID pandemic is that it was preceded by other coronavirus-related epidemics, such as SARS and MERS. We interviewed hospitals, doctors, facility managers, MEP engineers, and other industry experts before COVID-19, and airborne viral transmission was not on their radar. Frankly, researchers had been warning about such potential risks prior to the pandemic, and those warnings continue today (e.g., bird flu).
Climate change and human activities are threatening habitats, exerting pressure on the survival of other species. This is accompanied by increased interactions between people and wildlife, as well as a rise in human population density and global travel. These factors elevate the risks of disease transmission. Adapting and preparing for future scenarios is a wise and cost-effective thing to do, and the efforts have to begin now.
To prepare, it's important to recognize that COVID is not unique in its transmission mode, practically all of which occur indoors and between human occupants. Indoor environmental quality solutions capable of addressing pathogen spread are essential. To this end, we utilized CFD modeling and real-world testing to identify optimal air contaminant removal patterns and designed Tatama to more effectively meet this goal. We also subjected the Tatama to rigorous testing. With clean air delivery rates (CADR) of 410-450 CFM for viruses, bacteria, and mold at High mode, the results confirm capabilities double those of many competing systems. Onboard sensor data and analytics further allow us to improve system performance to mitigate transmission risks.
Sustainable Energy
Sustainable Energy Use Is Critical In Today’s World. What Makes Metalmark’s Technology Stand Out In Offering Clean Air Without The Heavy Energy Footprint?
Sissi Liu - We design our products with energy usage in mind. HVAC makes up about 40% of building energy use. Up to 50% of it can be attributed to the reconditioning of outdoor air for indoor air quality maintenance. Reducing the ventilation rate by targeting localized, distributed air cleaning with Tatama could significantly reduce net building energy use, carbon emissions, and operational costs.
In the case of HVAC filters, we know that MERV 13 or better mechanical filters–both glass and polymer–can effectively remove wildfire smoke. However, these filters are rarely used in commercial buildings as they come with high pressure, which drives up energy use while reducing HVAC equipment life. This is why the Sierra is unique–it increases smoke filtration efficiency without increasing the pressure of the base filter material.
Sustainability doesn't stop with energy and carbon footprint, however. In the development and production of our products, we also consider material safety and its impact on the environment.
Product Offerings
How Is Metalmark Planning To Evolve Its Product Offerings To Address Emerging Climate Resilience Needs In The Coming Years?
Sissi Liu - A problem that we discovered while studying indoor air quality is that there's a severe performance issue with sorbent materials for volatile organic compound (VOC) removal from the air. This is concerning because we spend over 90% of our time indoors. According to the US EPA, indoor air can be 2-5 times more polluted than outdoor air. Commercially available sorbent materials generally have poor gaseous chemical contaminant removal efficiency (<10%) and are unstable (e.g., can rerelease the chemicals) in real-world indoor air usage. They are especially bad at removing formaldehyde, which is a carcinogen generated indoors and occurs in high concentrations with wildfire smoke. Testing of sorbents typically uses low air flow rates and high chemical concentrations, neither of which is representative of real-world commercial building environments. Addressing VOCs is, therefore, critical for ensuring healthy indoor air quality in hospitals, schools, offices, and more. Because our proprietary material has sorption and catalytic properties, we plan to introduce it as a sorbent in Tatama to overcome known challenges in VOC removal. We also plan to add other products to our lineup, one of which is an IAQ sensor product, alongside the air cleaners and filters.
Into The Future
Looking Ahead, What Critical Challenges Will The Adaptation Sector Need To Address?
Sissi Liu - The adaptation sector has some major challenges to tackle. One of the biggest issues is that many people don’t fully understand how climate change is linked to increasingly extreme natural disasters, including wildfires, floods, hurricanes, and more. Without this understanding, it’s hard to build the urgency needed to take action. Another is the failure to appreciate the cascading effects of climate disasters beyond direct damages or loss of property and lives. Climate adaptation requires going beyond fortifying buildings against fires and floods and securing adequate insurance.
A second problem is funding. Climate adaptation investment makes up about 1% of climate tech VC funding. There's no particular US federal policy thesis on adaptation to fund R&D in this space. The diversity of technologies is even broader than that of climate mitigation.
Finally, adaptation tech solutions should be created with long-term sustainability in mind. This includes raw material, supply chain, energy use, end-of-life, impact on communities, land use, biodiversity, etc. Otherwise, as we create solutions to address adaptation, we could be adding to accelerating climate change problems.
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