Progress 06/01/15 to 01/31/17

Outputs
Target Audience:The target audiences reached by SDC's efforts during the reporting period include potential investors, potential collaborators and potential customers. As potential investors, SDC reached out to venture capital firms, companies involved in converting stored cereal grains into saleable products, companies involved in insect detection and control, and companies involved in storing bulk cereal grain.As potential collaborators, SDC reached out to a major firm involved in insect detection and fumigation and to a firm involved in bulk grain storage as potential collaborators.Those firms expressed serious interest and provide locations for field trials ofSDC prototype devices. SDC has targeted manufacturers of cereals, pet foods, grain-based food products and U.S. military quartermaster agents as potential customers for SDC's ultimate product. Changes/Problems:One of the insects, the sawtoothed grain beetle was eliminated from the work. Its pheromone, cucujolide, was not available, and the natural products synthetic chemists judged it nearly impossible to make.Also, the live insects were not available for use in the field trial. What opportunities for training and professional development has the project provided?The project provided broadened technical knowledge for SDC's science and engineering staff in the area of practical entomology. The variety of chemical compounds used by insects as semiochemicals to communicate is impressive. And knowing the classes of these chemical substances allows SDC scientist and engineers to tailor nano-crystalline sensor chips to respond selectively to each of these substances or classes of substances. How have the results been disseminated to communities of interest?SDC personnel attended the Annual Purdue Regional Pest Management Conference on January 10, 2017. A hard copy PowerPoint presentation was taken along to hand to interested parties at the conference. SDC is especially focused on soliciting interest on the part of the Department of Defense in SDC's work. Representatives of the Air Force registered to attend the Purdue conference. SDC is pursuing these contacts. The marketing effort has begun in that SDC prepared a poster describing how the multi-insect detector works for presentation at the Insects Limited-sponsored 12th Fumigants and Pheromones Conference in Adelaide Australia, 2016. This work was made possible by Insects Limited honoring its Phase I commitment to provide the facility, expert entomologists and live insects for the field test. Insects Limited sponsors a yearly conference at a different international location each year and publishes a newsletter read round the world. Past conferences have been held in Lübeck Germany, Bologna Italy, Chicago, York England and Thessaloniki Greece. Insects Limited believes that they will be able to sell "1000s" of the detectors to their customers. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? In this project, SDC successfully showed that its prototype device has the sensitivity and selectivity to detect RFB, WB, CB and IMM activity at low levels.This permits grain-based food product storage managers to avoid quality and dollar loss in stored food productscaused byinsect activity or infestation. The device is based on an array of six chips, each chip sensitized to a different insect pheromone. SDC arranged for Insects Limited to synthesize pheromones of the five most important insect pestsin stored products. The sawtoothed grain beetle's pheromone, cucujolide, was not available;the synthetic chemists judged it nearly impossible to make. So,it was eliminated from this project. The other four pheromones were acquired and used to make test gases, 2 ppm in dry N2 in "S" Al compressed gas cylinders to use with SDC's laboratory gas manifold. SDC extended itsSnO2 chips from uncatalyzed chips and chips catalyzed with Os, Pt, Ru, Mo to includeW and Pd catalysts, a set of seven catalyst options. Chip sensitivitywas measured by exposing each chip to dryair with 200 ppb of each of the four pheromones and calculating each chip's sensitivity to each pheromone by computing the chip conductance change per change in pheromone concentration: the Specific Net Conductance (SNC) in n-mhos/ppb. Ethanol and toluene were used as surrogates for alcohols and aromatic hydrocarbons. SNCs were measured at 0% RHand chip operating temperatures of 250oC, 300oC, 350oC and 400oC using five microchips simultaneously in SDC's prototype device.The SNC rangewas judged sufficiently broadfor selective pheromone detectionat concentrations down to 10 ppb whenbackground and interferantsare present up to 100 ppb. Bench tests with the prototypeshowed the ability of the chips to respond to thepheromones, thesignal size correlating with the gas phase pheromone concentrationinjected onto the chips. Pheromoneat 100 ppb, 200 ppb and 300 ppb in dry air wereinjected onto the chipsfrom SDC's lab gas manifold.Conductance changes were measured for 5 chips, un-catalyzed, Ni-, Pt-, Os- and Mo-catalyzed. SNC's were computed using the 200 ppb conductance change, SDC's standard protocol. This SNC was then used to compute pheromone concentrations from the conductance changes at 50, 100 and 300 ppb. The agreement with the pheromone gauge concentrations was good. With WB pheromone as an example, the calculated concentrations for the un-catalyzed chip were 40, 105 and 236 ppb...errors of 20%, 5% and 21%. The calculated concentrations have a linear correlation to the input concentrations with a statistical R2=0.98. Other pheromone/chip combinations show similar agreement. A "field trial"showed that SDC's pre-prototype equipped with the microchips from the bench tests responded with very good sensitivity to pheromones in the headspace over processed grain product (wheat flour) when live insects are present. The "field trial" was run at Insects Limited facility in Westfield, IN. The set-up used two galvanized pails, a "reference" of "clean" wheat flour always free of insects, and a sample of clean wheat flour into which vials containing the stored product insects (SPIs) were inserted. The vials contained different numbers of IMM, RFB, CB and WB. Insect Limited's Dr. Alain VanRyckeghem and Mr. Patrick Kelley provided the insects, ensuring that the individuals were of the right sex and in good physical condition. The "field trial" differs significantly from the bench experiments primarily in that many factors influencing the outcome of the "field trial" are outside the control of the operator, unlike the bench experiment where these factors are highly controlled. One example of such a factor is the pheromone concentration. Of course, during the bench testing the operator has complete control over pheromone concentrations. Live insects are unpredictable in their behavior with respect to pheromone production. The operator cannot predict the pheromone level during the "field trial". However, the technique allows for correlation of the chips' response to the insect number. This mimics the real world situation in which the final product will be used. The "field trial" protocol is described as follows. Abaseline was established by drawing headspace gas from the "reference" pail with "clean" wheat flour. After that,insects were placed into the "sample" pail.The insects were contained in vials including a small amount of the "clean" wheat flour to encourage insect activity. The vials had mesh tops, allowing the pheromone-containing headspace air in the vial to diffuse out into the headspace air in the pail. A "T" valve which connects the two pails to SDC's prototype lets the experimenter sample the headspace gas from the "reference" pail then switch to the insect-containing pail to compare its headspace gas to the "reference".After placement, the insects were left in place while headspace air from the "sample" pail was drawn to the device for 15-20 minutes. The flow to the device was then shifted to the "reference" pail while the insects were removed and replaced by the next insect sample. Insects were introduced in the following order and number: 50 WB, 250 RFB, 75 CB, 10 WB, 10 CB, 10 CB (replicate), 5 IMM, 25 IMM and 100 IMM were introduced. Device response to insect pheromones is reported as "net conductance", the change in chip conductance from "baseline" (headspace in the "reference" pail) to "sample" (headspace in the "sample" pail). "Net conductance" vs number of insects graphs show correlations between these two quantities. For example, the "net conductance" of an uncatalyzed chip with 5 WB present was 2 micromhos, with 50 WB present 8 micromhos. The IMM "net conductance" with 5 insects present was 2 microhms, with 100 insects present 4 microhms. The CB "net conductance with10 insects was 0.5 microhms, with 75 insects was 2.5 microhms. Both the warehouse beetle and the cigarette beetle give moderate to strong responses on each of the four chips displayed. The Indian meal moth gave a weak response. Insects Limited entomologists warned that the Indian meal moth is notorious for not producing pheromone consistently. The experiment was scheduled for late afternoon, a time when this insect is more likely to be active. Presumably, these unpredictable insects did not perform as expected. Field testing this prototype provided SDC with valuable experience that will be applied to improving device components in a Gen-2 production-worthy unit. Results to date indicate that all fundamental principles have been demonstrated, that a practical working embodiment of the technology operates as envisioned, and that there are no show-stopping barriers on the path forward. SDC intends to decouple the sensor device from the laptop computer and perform data processing and results calculation on the PC board. This approach enables signal transmission not only to the control room, but to individual product storage managers interested in product quality at the storage facility. SDC also discovered that chip sensitivity could be increased by changing the surface morphology of the sensor chip's sensory film by changing the calcining temperature in the manufacturing process from the usual 700oC to 600oC and to 500oC.Combined with catalyst addition to the semiconductor film and changing the chip operating temperature, this factor will increase SDC's ability to selectively detect target markers. SDC further learned that by using a defined protocol to select chips, improved concentration calculations are possible. The user chooses the Chip 1 with a large SNC for one of the target VOCs and small SNCs for all of the other VOCs. For Chip 2, the user chooses a chip with a large SNC for a different VOC than the one related to Chip 1 and small SNCs for all of the other VOCs, including the gas related to Chip 1. The same selection rule is used for Chip 3 and for every chip following.

Publications

• Type: Websites Status: Published Year Published: 2016 Citation: www.sensordevelopmentcorp.com (Capability Statement: Indianmeal moth)