Access Sensor Technologies is a small, efficient team of chemists and engineers that have extensive experience in research and product development. Our team has worked together for many years and are passionate about the products we create.

Located in beautiful Fort Collins, Colorado, our company was founded with the goal of developing simple, inexpensive, accurate environmental testing paradigms that can be used by everyone. Environmental diagnostics are very important to our society, yet historically have been prohibitively slow and expensive. Our goal is to develop technologies that make environmental diagnostics less expensive, faster, and ubiquitous, thereby making our world a safer and better place.

Dan Miller-Lionberg

Founder, Director of Engineering

Dan has a M.S. in Mechanical Engineering and an extensive background in a wide range of applied engineering. He is listed as an inventor on over ten patents and is an author on many academic manuscripts. Dan is a co-founder and the president of Access Sensor Technologies. He uses his engineering expertise to design and prototype analytical tools in the fields of environmental, water, and food analysis.

John Volckens


Dr. John Volckens is a Professor of Mechanical Engineering and the Director of the Center for Energy Development and Health at Colorado State University. He holds affiliate appointments in the Department of Environmental and Radiological Health Sciences and within the School of Public Health, the School of Biomedical Engineering, and the CSU Energy Institute. He earned his Ph.D. in Civil/Enivronmental Engineering from The University of North Carolina at Chapel Hill. His research interests involve air quality, low-cost sensors, aerosol technology, and air pollution-related disease. He is a founding member of the CSU Partnership for Air Quality, Climate, and Health – an organization that seeks to develop practical, science-vetted solutions to intertwined problems of air quality, climate, and health that we face as a society.

Charles Henry


Dr. Chuck Henry is the Chair of the Chemistry Department and a Professor of Chemistry and Chemical and Biological Sciences at Colorado State University. He received his Ph.D. from the University of Arkansas. Dr. Henry’s academic research is focused on environmental analysis, biosensor development, and paper-based and polymer-based microfluidics with detection via colorimetry and electrochemistry. His group has published over 100 peer-reviewed manuscripts in these areas. Chuck also has over a decade worth of experience with startup companies centered around analytical sensing devices.

Mark Schleiger

Chief Executive Officer

Mark has over 30 years of experience in business operations, product development, marketing, manufacturing, channel development, and service/support experience in technology and service based companies. Over the past 15 years, he has successfully helped mentor, launch, and develop dozens of startups in a wide range of markets.  Mark has a M.S. from Colorado State University in Business Management and has completed LabCorps Lean Start-up and LEAN launch pad programs.  Mark excels at keeping things simple and focused to drive innovative products to market.

Thomas Reilly

Chief Scientific Officer

Tom is the lead chemist at Access Sensor Technologies. He is currently advancing the National Science Foundation Phase II SBIR project to develop low-cost test strips for quantitative metal determination in water. In addition, Dr. Reilly is the PI on a recently awarded USDA-NIFA Phase II SBIR project which aims to develop a low-cost testing platform for foodborne bacterial pathogens. Both technologies were conceived at Colorado State University in Dr. Charles Henry’s research group. Tom has additional roles at the company related to partnerships and business development. His background includes a Ph.D. in Analytical Chemistry, postdoctoral work at the National Renewable Energy Lab as well as training through the Kaufman FastTrac program.

Josephine Hofstetter

Research Director

Josephine received her B.S. in Chemistry from Colorado State University and Ph.D. in Analytical Chemistry from The University of Texas at Austin. She has a strong background in developing highly sensitive point-of-need chemical and biological sensors that maintain the simplicity that’s necessary for such devices. She has three patents and multiple publications, all directly related to point-of-need diagnostics.

John Wydallis

R&D Scientist

John graduated with his Doctorate in Chemistry from Colorado State University in 2016. His graduate work was on designing a microfluidic and CMOS microchip platform that could image chemical reactions with high spatial and temporal resolution. He has an extensive background in microfluidics and miniaturization of analytical systems. His rapid prototyping abilities include 3D printing (extrusion and stereolithography), laser cutting and engraving, hot embossing, and lithography. He is passionate about product development and has been directly involved in multiple research and development projects over the past three years.

Kai Fuller

R&D Chemist

Kai received a bachelor’s degree in chemistry from Colorado State University in 2017. During his undergraduate work, he performed research that focused on synthetic organic chemistry.  Kai’s main role at Access Sensors is advancing the development and manufacturing of the On-Target detection technology.

Mollie Phillips


Mollie received her degrees in Mechanical Engineering and Biomedical Engineering from Colorado State University. She has extensive experience designing and building prototypes, as well as experience in large scale manufacturing. Mollie is working to advance and streamline manufacturing techniques for existing products at Access Sensor Technologies as well as assisting in the research and development of new products.

Gabe Neymark


Gabe is a senior mechanical engineering student at Colorado State University. Throughout his undergraduate career Gabe has worked with Engineers Without Borders to establish a potable water distribution system in La Criba, El Salvador. He began working with Access Sensor Technologies in 2017. At Access Sensors, Gabe works on projects to develop new technology for water quality and soil quality analysis.

Walt Grady


Walt has over 25 years of experience leading customer facing change as a program and project manager. His marketing and business development background includes extensive experience leading cross-functional and project teams in both business and government that were focused on alignment with customer needs.  Walt has a M.S from Pepperdine University’s Business School. Walt’s main focus is on embedding customer needs into product and processes.

Chloe Beardsley

Chemistry Intern

Chloe is currently in her sophomore year of college working towards earning her B.S. in Chemistry from Colorado State University. As well as working as an intern at AST, she does academic research with the Henry group at CSU. Her work with that group is focused on the development of paper-based analytical devices used for environmental analysis. After earning her degree, she plans to share her passion for chemistry through teaching.

Mikaela Zinn

Marketing and Sales Intern

Mikaela is going into her last year at Colorado State University, working towards a degree in economics with a minor in business. After obtaining her degree she plans to spend some time travelling overseas and learning more about different economies. Mikaela has grown up in a marketing environment working with her mom. She will help Access Sensor Technologies expand their marketing and sales capabilities.

Dani Hatton

Marketing and Sales Intern

Dani is a senior at Colorado State University studying Business Administration with a double concentration in Management and Marketing. She is excited to contribute to AST’s CRM system while expanding her marketing skills and knowledge. After graduation she hopes to pursue a digital marketing career.

Jake Jensma

Engineering Intern

Jake is a Colorado native who is pursuing an undergraduate degree in Chemical Engineering at Montana State University. At Access Sensors, Jake is developing an image analysis app that reads On-Target cards. Jake enjoys programming and outdoor activities.