Source: FLORAPULSE CO submitted to NRP
PLUG AND PLAY, INEXPENSIVE WATER POTENTIAL SENSOR FOR WIDE USE IN SMALL-STEM CROPS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
ACTIVE
Funding Source
Reporting Frequency
Annual
Accession No.
1031178
Grant No.
2023-40000-40786
Cumulative Award Amt.
$650,000.00
Proposal No.
2023-04028
Multistate No.
(N/A)
Project Start Date
Sep 1, 2023
Project End Date
Aug 31, 2026
Grant Year
2023
Program Code
[8.4]- Air, Water and Soils
Recipient Organization
FLORAPULSE CO
170 LOUISE LN
DAVIS,CA 95618
Performing Department
(N/A)
Non Technical Summary
Plant water status dramatically affects crop yield and quality, but growers lack tools to measure water status accurately, automatically, and long-term. This leads to preventable crop losses and excess water use. FloraPulse has demonstrated the only sensor that meets these requirements, a microtensiometer that directly measures water potential in the plant stem, but the current sensor probe and installation method are too large for a majority of commercial crops.We will develop a probe that is user friendly, reliable, and dramatically smaller to allow widespread water potential measurement in stems as little as 6 mm, then validate the sensor installation method in the laboratory and multiple commercial small-stem crops. We will improve sensor sensitivity and speed through changes in the microchip fabrication; develop a laboratory 'osmotic system' to simulate a tree installation for quickly testing sensor performance; develop improved sensor and hardware for installation, and develop an MVP comprising an inexpensive datalogger, smartphone app, irrigation guidelines, and improved user interface. These system improvements will be field tested by our collaborators in grape, cotton, blueberry, soybean, and apple rootstock crosses across 4 states (CA, NY, OR, AZ).The small-stem sensor developed will enable real-time water potential measurement in crops worth over $500 billion worldwide and could lead to 20% yield increases and 20%+ water savings.
Animal Health Component
15%
Research Effort Categories
Basic
15%
Applied
15%
Developmental
70%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
1111119202033%
4041199202033%
1021099202034%
Goals / Objectives
The overarching goal for this project is to develop a robust, easy to install, relatively inexpensive water potential sensor for crops with small stem sizes; to be used by scientists and growers. Such a tool will help answer outstanding questions in plant science and improve water use efficiency and crop health. More specifically, we have 4 goals.Goal 1. Improve the microchip response time, sensitivity, and size.Use <110> Si wafer fabrication to increase porous Si permeability and speedUse of n-doped crystalline <100> oriented piezoresistors for 3× sensitivity improvement.Addition of bossed diaphragm for 10x sensitivity improvement.Goal 2. Test and tailor probe and installation hardware for small crops.Develop methods to evaluate sensor improvements in artificial stem, osmotic test, and field test.Improve installation hardware with lab and field testing.Test variety of mating compounds and mixtures to increase stability and speed.Develop easy to use installation guide system.Harden sensor design and install process for frost tolerance and re-usability.Goal 3. Field test sensor improvements in small crops to get ready for commercialization.Test in 5 small stem crops: winegrape, cotton, blueberry, soybean, apple.Goal 4. Develop minimum viable product (MVP) for small cropDevelop initial irrigation guidelines.Develop datalogger and sensor electronics tailored for small-crop applicationsDevelop user interface for small cropsSmartphone appPrepare suite of manuals and videos for use
Project Methods
This project involves various avenues of research.Microfabrication - processes for building the microchip tensiometer will be developed, tested and improved to achieve better performance. This effort involves cycles of building microchips, then testing their characteristics. The new microchips should have faster response, be smaller, and more sensitive.Laboratory testing - installation methods will first be tested in the laboratory under controlled conditions. This will involve building simulations of field conditions and plant response in the laboratory, then testing installation performance.Field testing - Sensors will initially be field-tested by FloraPulse staff. This testing will help us understand the installation method and improve it for robustness and ease of performance.Trials with collaborators - Sensors will be tested by collaborators, to whom we will provide instructional videos, and feedback on the data.Test with growers - the final round of testing will be with typical growers, who will perform the sensor installation themselves and provide feedback on (1) sensor ease of use and (2) usability of the data.Overall, the installation hardware and methods will be evaluated for (1) robustness and (2) ease of use.The results here will be communicated with audiences through tradeshows, conferences, email blasts, LinkedIn posts and blog posts.

Progress 09/01/24 to 08/31/25

Outputs
Target Audience:PLANT SCIENTISTS - research efforts and progress on developing the small-crop microtensiometer sensor was communicated to scientists regularly through our mailing list. We also had strong and ongoing collaboration with professors at UC Davis, U of Arizona, Cornell and others. AGRICULTURAL GROWERS - FloraPulse marketed the research and product developed under this SBIR to agricultural growers in California and worldwide. A number of news articles were written on our technical accomplishments. Changes/Problems:No major changes to report. We continue making many smaller improvements to the sensor, installation system, and instructional manuals/videos. What opportunities for training and professional development has the project provided?FloraPulse hired and trained 4 intern Engineers to work on various parts of this project. These students received mentorship and training in computer programming, firmware development, artificial intelligence and app development. Each of them got to discuss their projects in detail with the CEO. How have the results been disseminated to communities of interest? The research performed here has been disseminated through many means, particularly in various news outlets (see below). May2025From PhD to CEO: Michael Santiago on Innovation in AgTech CADclass Podcast - Joshua Manley May2025Plant moisture monitors help to optimize irrigation AgAlert - Vicky Boyd Dec2024Using embedded irrigation sensors to better understand water use Tip of the Iceberg Podcast - Christina Herrick Oct2024Moisture Management in Peaches Soil Doctor - Bryant Mason What do you plan to do during the next reporting period to accomplish the goals?Work on goals 1-4 continues for the next year. Goal 1. We have hired a dedicated cleanroom engineer to tackle this goal full-time, starting in September. Goal 2. Now that the sensor is being sold, we are talking to users and receiving feedback on what aspects can be improved. The installation equipment and methods will be improved using this feedback. Goal 3. The sensor continues being tested in new crops, such as walnut, cotton and soybeans by our collaborators. We started a new round of testing this July that will go through November 2025. Feedback and results from this testing will be used for sensor improvements. Goal 4. The big priority here is to finish developing the smartphone app and launch it. We have a full-time programmer that will continue this work. We will also engage with users to develop rudimentary guidelines for the new crops, such as blueberry.

Impacts
What was accomplished under these goals? Goal 1. We have acquired the <110> wafers and developed the photomask for this test. The work will be done later this year once we hire a cleanroom engineer. Goal 2. Sensor installation tools and protocols have been improved dramatically. We have recorded instructional videos and written manuals for installing the sensors. We further developed a toolbox to be included with each microtensiometer order - it contains a variety of custom-made tools for sensor installation. Each tool, most of them 3D-printed, has gone through 5-10 design iterations to increase reliability and ease of use. Goal 3. Sensor development has proceeded extremely well and we are now selling the probe being developed under this grant. Testing in small crops was performed successfully, and we developed multiple versions of the sensor installation equipment for various crop sizes and types (7mm, 3mm, 2mm, thick bark trees, walnut). The sensor performed well in winegrape, cotton, blueberry and apple. Validation in soybean is still ongoing. Goal 4. A minimum viable product has been mostly developed and is being sold to customers.We still need to finish building the smartphone app and develop inital irrigation guidelines for many of the crops tested. We did record and write a thorough suite of videos and manuals for sensor installation and use.

Publications


    Progress 09/01/23 to 08/31/24

    Outputs
    Target Audience:PLANT SCIENTISTS - research efforts and progress on developing the small-crop microtensiometer sensor was communicated to scientists regularly through our mailing list. We also had strong and ongoing collaboration with professors at UC Davis, U of Arizona, Cornell and others. GROWERS - initial field testing of the sensors was performed by growers of various crops. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?FloraPulse sends out a monthly mailing list that goes over our recent research accomplishments. This email goes out to researchers and growers worldwide. We also presented results at the Lab-Ferrer workshop in Spain (February 5, 2024) and the IFTA conference in Yakima, WA (February 11, 2024). What do you plan to do during the next reporting period to accomplish the goals?Goal #1 We did the groundwork for Goal #1 by developing the microfab plan, ordering the parts, and making new photolith masks. We also performed a fabrication to build chips for this phase of testing. During the next reporting period, we plan to test a new SiO2 photolithography mask that we believe could dramatically speed up the sensor response time. With a faster sensor, it becomes possible to increase the sensitivity by thinning out the sensing diaphragm. The microfab will further be fine-tuned in numerous ways to increase yield and decrease manufacture time. Goals #2 and #3. Progress on Goals #2 and #3, to develop and test the sensor installation for small crops, has been phenomenal. We've shown that sensors can measure water potential in small crops such as blueberry, cotton and grapes. The installation method is relatively straightforward and we've created videos on how to install sensors. Work on these goals will continue nonetheless, in particular to continue improving the sensor's reliability and ease of use. More testing and development is definitely needed to make our sensors work reliably in avocado and walnut, for instance. We also plan to test sensors in other crops, such as corn and tomatoes. Tasks to be done for goal #2 and #3: Design and test new installation hardware and tools Tweak and improve the installation method for: small crops, thick-bark crops and walnut/avocado (require a different install method to avoid the tree wounding response) Record updated installation videos, and write up instruction manuals Test updated sensor designs in field crops, FloraPulse and partners Improve sensor manufacture to increase yield and overall reliability Goal #4 Regarding goal #4, we will do the following: Continue development of the FloraPulse app and actually deploy it to our customers for testing Make small improvements to the datalogger and sensor electronics Engage with scientists to develop irrigation guidelines for each crop Record new versions of the installation videos.

    Impacts
    What was accomplished under these goals? Goal 1. Wafers were ordered and a step by step plan was developed. A new photolithography mask for SiO2 was designed and manufactured. Goal 2. Extensive methods were developed to test the probe prototypes. First, an artificial tree system was built and tested, then used to test probes. This system allowed measurement of the probe response time and propensity towards errors due to temperature or drying out. Second, we built a system to test sensor propensity to freeze under field conditions. We found that sensors can sometimes withstand temperatures down to -20C; this was an unexpected result. Third - we tried to build an osmotic test system, but determined that this setup was very difficult to do properly, and is not worth pursuing because the data is irrelevant to field conditions. Many iterations of installation hardware were manufactured and tested in the laboratory and field. We successfully built hardware that appears (so far) to work properly and reliably in the field trials started this year. The hardware has been made significantly easier to use over time, but this effort is still ongoing. Multiple mating compound formulations were tested and we picked a 'winning' formulation. A standard operating procedure was written to reliably make this mating compound. We found that a combination of kaolin clay and DI water works best. Sensor manufacture has been improved, which led to better sensor reliability and re-usability. At the moment, an estimated 90% of all tries at re-using a sensor are successful. Goal 3. The small sensors were tested by our partners in the following crops: avocado, blueberry, cherry, orange, grape, hazelnut, kiwi, prune and walnut. Results in all these crops were positive, but there were reliability issues, in particular with walnut and avocado. Research and improvements are ongoing. Goal 4. The FloraPulse smartphone app has gone through multiple iterations and we have a barebones app that shows the data and recommended levels. We recorded videos on how to install the small sensor version into small crops and into thick-bark trees.

    Publications