Defend your personal space with this wearable device

Maker builds an over-sized, electro-mechanical backpack with a shoulder-mounted, self-firing Super Soaker. 

Don’t you hate when people invade your personal space and get up in your business? What better way to send a message than by squirting them with a water gun? However, having to manually target people with your soaker of choice can be a tedious task, especially if there is an entire army of time-wasting, close-talking friends or colleagues approaching you. Luckily, there’s an automated solution that will do the trick. Introducing the Personal Space Defense System (PSDS)


The brainchild of DJ from Instructables, the system is described as an “over-sized, electro-mechanical backpack with a shoulder-mounted, self-firing water gun.” While this isn’t the first robotic buffer zone defender, it’s perhaps one of the coolest — and most applicable nevertheless. (Anouk Wipprecht’s Spider Dress is still pretty sweet, too!)

How it works is pretty straightforward: If someone encroaches upon your personal space, an embedded sensor pendant will detect the invader and the Super Soaker Electro Storm will blast a few shots of water towards them.


Aside from the stripped-down water gun, the Maker employed several electronic components to make the project a reality. These included an Arduino Micro (ATmega32U4), an IR distance sensor, a PIR motion sensor, a laser diode, a power switch, an illuminated switch, a 2200mAh 7.4V LiPo battery, a voltage regulator, a MOSFET, a bunch of resistors, a transistor and a capacitor, as well as a number of other off-the-shelf supplies.

The PSDS is comprised of three main parts: a shoulder-mounted water gun, a sensor-laden necklace and a trigger mechanism. As AJ explains, pressing the power button activates system while pushing the trigger button will toggle between armed and disarmed modes. Once the system is armed, the gun will flip up and the attached laser diode will power on.


What’s more, he removed the original case of the Super Soaker to reduce the weight and allow for easy direct electrical control. This enabled him to wedge the water gun and reservoir into a channel bracket and actuate it by a geared servo.

“For ease of mounting and added comfort, I designed the system to be mounted to a regular backpack. The pack provides a sturdy mounting point for the main tube and proto-board for the electronics,” AJ adds. “The gun assembly is a bit hefty, so to balance out its inherently wobbly nature, I created a counterweight that has a mount for a camera. I ended up attaching a GoPro.” (This will surely capture some hilarious clips!)

The program running the PSDS is a basic Arduino sketch, which the Maker has made available, along with the Bounce library that will need to be installed. Those wishing to build a personal space defending wearable of their own can head over to AJ’s Instructables page, where you’ll find a detailed breakdown of the project.

2 thoughts on “Defend your personal space with this wearable device

  1. Pingback: Rewind: 35 absurdly awesome Arduino projects from 2015 | Atmel | Bits & Pieces

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