Final Report: Multi Air Pollutant Lab-On-a-Chip (MAPLOC)

EPA Contract Number: EPD15039
Title: Multi Air Pollutant Lab-On-a-Chip (MAPLOC)
Investigators: Singh, Mahendra
Small Business: Waddan Systems LLC
EPA Contact: Manager, SBIR Program
Phase: I
Project Period: September 1, 2015 through February 29, 2016
Project Amount: $100,000
RFA: Small Business Innovation Research (SBIR) - Phase I (2015) RFA Text |  Recipients Lists
Research Category: Small Business Innovation Research (SBIR) , SBIR - Air and Climate


The concern over the environmental and health risks associated with the emission of hazardous air pollutants and volatile organic compounds has led to a pressing need for affordable and reliable ways to detect and quantify the presence of these pollutants. The goal of this effort is to develop a low cost miniature quick-responding device suitable for continuous monitoring networks at potential polluting sites. The next generation air monitoring effort promoted by the EPA is targeted to prevent uncontrolled and accidental release of pollutants by monitoring the air near the pollutant sources, so that the problem can be nipped in the bud.  This research is targeted towards producing a commercially viable device to form continuous pollutant monitoring networks. The device employs silicon carbide nanowires in combination with a self-assembled layer of organic molecules on an optically sensitive waveguide.

Summary of Findings:

With conventional processing equipment, we can produce a sensor with a set of parallel nanowires and optically sensitive waveguide using batch processing methods.  It is feasible to produce and package the entire MAPLOC (sensing element and electronics) in a 50mmX20mmX4mm volume.

Testing of the sensing elements produced by the first fab iteration in a gas-tight box yielded a response time of less than 1.7 minutes (~100 sec).  A significant portion of the response time delay can be attributed to the long feed tube attached to the box.


  • A single micromachined combo sensor is the best choice for the MAPLOC.  Several (24) of these devices can be built in a three inch wafer.
  • It is feasible to manufacture a low cost MAPLOC using commercially available electronic  ICs along with the combo sensor mentioned above.
  • ZigBee provides the best networking for the MAPLOC.  A battery operated MAPLOC can sleep for a long time with trickle (90 µW) power consumption.
  • Power management schemes can significantly extend the battery life.  As even during the active mode, the MAPLOC needs to stay awake only for 2 to 3% of the time during each measurement cycle.
  • The highly integrated ICs—one microcontroller, one regulator, one transceiver—yield a compact device with very small foot print (20mmX20mm).
  • The estimated price of the MAPLOC per node is under one hundred dollars..


We had discussions and telecoms with local southern California companies, which use gas sensors in their products.  A few have agreed to field test MAPLOC.

A Foresight report recommended three companies--RAE, TSI, and Instrument Systems Corp. (ISC)—as interested in MAPLOC.  We are continuing our dialog with these companies.

We have also designed a sustaining business vehicle for MAPLOC as a part of Global Air Monitoring Systems.  It is planned as a dedicated subsidiary for production and marketing of MAPLOC.

  • Phase I:   Concept Development (will be completed as EPA SBIR Phase I)
  • Phase II:  Prototype Development & Beta Field Testing (EPA SBIR Phase II)
  • Phase III:   Production and Market Penetration
  • Phase IV:   Initial Public Offering (IPO) for Global Air Monitoring Systems to be run as an independent company.