Nonviolent self-defense

Sexual Violence Stinks

A bracelet that emits a repellent smell in an emergency, protecting the wearer from attack – with this innovative contribution to preventing sexual violence, the “invi bracelet” was the winner of Siemens Stiftung’s empowering people. Award in 2016.

One in 20 women in Europe have been the victim of rape. A global problem, sexual violence is all around us, and not all its victims are women. Nevertheless, the issue is repeatedly shrouded in silence, with victims left to cope by themselves. Roel van der Kamp wants to change that.

While looking for a non-violent but effective weapon against sexual assaults, he had a new idea: a bracelet that can be activated when its wearer is in danger, putting victims and witnesses back in control. How? Van der Kamp’s “invi bracelet” simply releases a repellent smell when the wearer is attacked. Yet this is enough to completely surprise the perpetrator and disrupt their intentions. It not only hinders the attacker’s sexual arousal, but also alerts potential bystanders.

Roel van der Kamp, your inspiration for this unusual method of self-defense came from nature: Skunks use exactly the same technique to protect themselves against attackers. How long did it take to turn this idea into a working product?
Almost three years. We started by talking to a large number of victims, psychologists, police officers and neuroscientists to learn about all the different aspects of violent attacks and their prevention. Then we had to develop the bracelet itself – neither the smell nor the activation mechanism had yet been developed. The formula for the substance that releases the odor was created with the help of an international research project at the University of Groningen. It needs to have optimal impact while remaining non-toxic and ethically sound. Self-defense experts tested the bracelets for us in simulated attacks to ensure that they could be safely used.

Has the “invi bracelet” been used in any emergencies yet?
Not yet, and hopefully it will stay that way. The mere decision to acquire the bracelet is the beginning of a determination to take a stand against sexual violence, and this makes us more resilient. If we are attacked, we feel less overwhelmed and can react more effectively as a result. Pilot studies confirm that wearers of the bracelet feel safer and stronger, and therefore behave with more self-confidence. This alone reduces the risk of becoming a victim. If the worst does happen, however, invi can make a decisive difference and prevent escalation.

invi initiator Roel van der Kamp (center) at the international empowering people. Network workshop on organizational development in Amsterdam in November 2017

“invi bracelet”: the attractively designed bracelet is a non-violent means of self-defense.

How did you finance invi, your social start-up?
We are self-financing at the moment. There are no major external investors. But a great many people are supporting us with help and advice because they also want to do something to tackle sexual violence. That’s extremely encouraging.

Sexual violence is a global problem. It’s often particularly difficult for women in emerging countries to defend themselves.
Our aim is to protect people from sexual assault all around the world. In the future, we want the bracelet to be affordable for men and women in developing and emerging nations. One possibility, for example, would be to finance it using a hybrid model. This means that sales in Europe would cross-finance bracelets in poorer countries. This would, of course, rely on collaboration with a local organization that works in the area and has the experience to judge whether and how invi could work in the relevant social context.

What are your next steps?
All this requires a sound economic basis and infrastructure. Having concentrated so far on product development and established an online shop in the Netherlands, we are now looking for partners in other European countries. Our membership in the
empowering people. Network is essential for taking these next steps. Not only the prize money for product development, but also the recognition has been key. We have learned a lot from our exchanges with other social entrepreneurs and it has shown us that we are not fighting alone. Only by combining forces can we turn #MeToo into #NotMe.

Bracelets can be ordered from

Imprint by courtesy of the magazine enorm:

Find more information about invi as the award-winning solution from 2016 here:

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