Let me start with some questions.
Have you lost all samples in a freezer because of power outrage? Have you made
your family unhappy (or happy) because you spend more time with laboratory rats?
Have you failed to collect soil samples after a long boat trip because of unpredicted
high water levels? Have you found out that super high phytoplankton production was
caused by your advisor accidentally turning on a light during dark cycles?
It is not uncommon to hear these kinds of unfortunate events
from fellow scientists. It looks almost inevitable for biologists to avoid them
because nature is full of surprises and that’s why we love studying biology! But
would it be nice if you had a robot preventing unwanted events from happening? In
addition, it would be even better if a robot is easy to program, make, and,
most importantly, affordable. We tend to think that a robot is an intelligent
object with arms, legs, or at least blinking eyes like a Disney character Wall-E.
But the definition of robot on Wikipedia is rather simple: “A robot is a
machine… capable of carrying out a complex series of actions automatically.” Thanks
to a boom of open-source platforms, we can make a robot under $10.
Arduino is an open-source micro-computer
that can read inputs and send outputs. For examples, a combination of Arduino
with a sensor and a communication device can detect a change (input), activate
a physical device (output), and report programmed messages on the web, email,
your phone, or Twitter (output). If you can make a formula on Excel, you are
coding already. To help you understand a function and capability of Arduino, I
will share my recent project below (Fig. 2):
- Project: Chloe’s pulse monitor
- Purpose: I want to examine Chloe’s heartbeat in response to the sight of different objects such as a treat or a cat. Her pulse will be continuously collected on the cloud service and analyzed for detecting an unusual pattern of Chloe’s pulses. If her heartbeat is unusually high, I want to be notified remotely.
- Materials: Dog, cat, treat, Particle Photon (Arduino with Wi-Fi capability) (https://store.particle.io), pulse sensor (https://pulsesensor.com), battery, Thingspeak (open-source cloud service) (https://thingspeak.com), IFTTT (open-source notification service) (https://ifttt.com), cell phone
Chloe’s pulse turns out to be a reliable variable to measure
her status/conditions (Fig. 3). When I showed her a chicken treat (the first
peak), her pulse went up and dropped rapidly within 40 seconds. When she saw a
cat (the second peak), her pulse went up and dropped gradually for more than 2
minutes. Indeed, the sight of a cat infuriated Chloe so much that Chloe spit out
the treat and almost ran into the window! If I have more data and can find a
correlation between pulse patterns and her behaviors, I would be able to tell more
about Chloe’s status/conditions remotely. Can you think of other applications
with the same robot? What other sensors would you add to monitor new variables?
What other communication methods would be appropriate for different purposes (e.g.,
radio frequency, Bluetooth, Wi-Fi, Telephone system (SMS), or Internet (TCP/IP))?
I
have used a series of micro-controllers and off-the-shelf electronics (e.g.,
pumps, valves) to simulate saltwater intrusion in natural wetlands (Fig. 4). A
waterproof ultrasonic distance sensor is used to measure water levels in the
creek where the main pumps were located. Creek water is delivered into water
tanks and premade brine water is delivered into one of tanks to prepare
brackish water every high tide. During low tide, the water is gravity-fed through
solenoid valves and meters out to each plot. The entire system consists of 5
pumps, 10 solenoid valves, 2 flow meters, 4 sensors, solar panel, 3 large
tanks, and Arduinos at a cost of $1800 (Lee et al. 2016. Link: http://link.springer.com/article/10.1007/s13157-016-0801-4). Not bad price, isn’t it?
I like to finish with an inspiring quotation: “Logic will get
you from A to B. Imagination will take
you everywhere.” If you can build a robot, you will be able to test almost
anything you can imagine. Happy making!