Called 21 Grams, the box is made from layers of wood, which are glued together and hand-sanded to create the final shape then coated with a pale grey matt finish. It opens using a gold-plated brass key that can be worn as a necklace, and incorporates an amplifier for playing music from an iPhone that slots into the base.
It also contains a scent diffuser and a small gold-plated urn that holds up to 21 grams of ashes inside a blown-glass dildo.
"21 Grams is a memory-box that allows a widow to go back to the intimate memories of a lost beloved one," explained Sturkenboom. "After a passing, the missing of intimacy with that person is only one aspect of the pain and grief. This forms the base for 21 Grams. The urn offers the possibility to conserve 21 grams of ashes of the deceased and displays an immortal desire."
"By bringing different nostalgic moments together like the scent of his perfume, 'their' music, reviving the moment he gave her her first ring, it opens a window to go back to moments of love and intimacy," he said.
When unlocked, the front of the box forms two panels that fold out. One of these holds a built-in perfume container with a rubber diffuser attached.
A drawer in the base of the box can be used for keepsakes like a handkerchief or small scarf. The inside of the lid also features a round storage compartment for a ring, which is hidden behind two hinged flaps that form the shape of a shield when closed.
The hollow glass dildo rests at the back of the main compartment, and the small golden urn is slotted in to the bottom of this and closed with a brass seal.
Music from the user's iPhone is amplified by the box, with the sound transmitted through perforations arranged in the shape of two forget-me-not flowers on the inside of the box.
The device was shown during Milan design week in the Ventura Lambrate district alongside other products by Sturkenboom. These included a table-clock called Watching Time Fly, which has no hands and tells the time with a small model of a fly made from a €500 note that completes a full revolution around a glass dome every minute.
The Utrecht-based designer graduated in 2012 from the Netherlands' Artez Academy for the Arts, and has since focused on producing limited-edition pieces that reinterpret familiar products to examine themes of love, time and value.
The idea for 21 Grams, which is handmade to order and can be personalised to the requirements of the customer, grew from his relationship with an elderly widow.
"I sometimes help an elderly lady with her groceries and she has an urn standing near the window with the remains of her husband," said the designer. "She always speaks with so much love about him but the jar he was in didn't reflect that at all."
"In that same period I read an article about widows, taboos and sex and intimacy and then I thought to myself: 'can I combine these themes and make an object that is about love and missing and intimacy?'"
The name of the project refers to a belief that a human soul weighs 21 grams. This is based on a series of early 20th-century experiments by an American doctor that recorded weight loss in people as they died, which have since been widely discredited.
"I tried to open a new window for the way we reminisce about someone and find a dialogue for these feelings people are struggling with when somebody passes," said Sturkenboom.
"We live in a time where we are able to manipulate life, adjust the way that we look, where the possibilities are endless if it comes to body enhancements, but there is one thing we still cannot answer, the unavoidable passing of life. But I can sure try."