Water-walking Ninjas

Gerridae, or water striders, have the unique ability to stand and walk on the surface of water. Their feet are densely covered in uneven hairs, which make them water-repellent and keep them from breaking the surface tension of water. This surface tension can support 15 times the body weight of the insect with just one leg touching. Gerridae propel themselves forward by using their middle legs to kick the water’s surface, and doing so they can move at speeds of up to one meter per second.

Defense/Stability:: Water repellent

Energy creation

Nature. 2004; 432:36.

Researchers have spent some time studying the movements of the gerridae by analyzing video of the insects. They have successfully built a prototype of an ultralight robot (about 1g) that can move on the surface of water. The material cost of the prototype is quite cheap at about 1,000 yen (approximately $12.50).

Robots capable of walking on water.

By mimicking the movements of the gerridae, it could be possible to build robots that are able to freely roam about on the surface of water. Chemical sensors could be installed in these robots to check for the presence of toxic substance in potential sources of drinking water. If equipped with cameras, these robots may be useful for reconnaissance, surveillance, and exploration.

Query	Affected	Num. rows	Took (ms)	Actions
SHOW FULL COLUMNS FROM `contents`	16	16	2	maybe slow
SELECT CHARACTER_SET_NAME FROM INFORMATION_SCHEMA.COLLATIONS WHERE COLLATION_NAME= 'utf8_general_ci';	1	1	1
SHOW FULL COLUMNS FROM `users`	10	10	9	maybe slow
SHOW FULL COLUMNS FROM `groups`	4	4	1	maybe slow
SHOW FULL COLUMNS FROM `permissions`	5	5	1	maybe slow
SHOW FULL COLUMNS FROM `groups_permissions`	3	3	1	maybe slow
SHOW FULL COLUMNS FROM `groups_users`	3	3	9	maybe slow
SHOW FULL COLUMNS FROM `contents_searches`	6	6	1	maybe slow
SHOW FULL COLUMNS FROM `attachments`	11	11	9	maybe slow
SHOW FULL COLUMNS FROM `attachments_revs`	13	13	1	maybe slow
SHOW FULL COLUMNS FROM `contents_related_items`	5	5	9	maybe slow
SHOW FULL COLUMNS FROM `related_items`	6	6	1	maybe slow
SHOW FULL COLUMNS FROM `contents_related_items_revs`	8	8	9	maybe slow
SHOW FULL COLUMNS FROM `contents_tags`	5	5	1	maybe slow
SHOW FULL COLUMNS FROM `tags`	7	7	1	maybe slow
SHOW FULL COLUMNS FROM `tag_groups`	6	6	1	maybe slow
SHOW FULL COLUMNS FROM `contents_tags_revs`	7	7	1	maybe slow
SHOW FULL COLUMNS FROM `contents_revs`	18	18	1	maybe slow
SELECT `Content`.`id`, `Content`.`user_id`, `Content`.`last_edit_user_id`, `Content`.`post_date`, `Content`.`post_date_year`, `Content`.`post_date_month`, `Content`.`post_date_day`, `Content`.`title`, `Content`.`title_en`, `Content`.`content`, `Content`.`plain_content`, `Content`.`page_view`, `Content`.`flag`, `Content`.`mod_count`, `Content`.`created`, `Content`.`modified` FROM `contents` AS `Content` WHERE `id` = 181 LIMIT 1	1	1	0
SELECT `Attachment`.`file_name`, `Attachment`.`dir`, `Attachment`.`model`, `Attachment`.`foreign_key` FROM `attachments` AS `Attachment` WHERE `file_name` <> 'default.jpg' AND `Attachment`.`foreign_key` = (181)	2	2	0
SELECT `ContentsRelatedItem`.`content`, `ContentsRelatedItem`.`related_item_id`, `ContentsRelatedItem`.`content_id` FROM `contents_related_items` AS `ContentsRelatedItem` WHERE `ContentsRelatedItem`.`content_id` = (181)	11	11	0
SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 1	1	1	0
SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 2	1	1	0
SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 4	1	1	0
SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 6	1	1	0
SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 7	1	1	1
SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 8	1	1	0
SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 9	1	1	12	maybe slow
SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 9	1	1	6	maybe slow
SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 9	1	1	0
SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 11	1	1	0
SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 12	1	1	0
SELECT `ContentsTag`.`id`, `ContentsTag`.`tag_group_id`, `ContentsTag`.`mod_count`, `ContentsTag`.`tag_id`, `ContentsTag`.`content_id` FROM `contents_tags` AS `ContentsTag` WHERE `ContentsTag`.`content_id` = (181)	2	2	0
SELECT `Tag`.`name`, `Tag`.`comment`, `Tag`.`tag_group_id` FROM `tags` AS `Tag` WHERE `Tag`.`id` = 85	1	1	0
SELECT `TagGroup`.`code`, `TagGroup`.`name` FROM `tag_groups` AS `TagGroup` WHERE `TagGroup`.`id` = 6	1	1	0
SELECT `Tag`.`name`, `Tag`.`comment`, `Tag`.`tag_group_id` FROM `tags` AS `Tag` WHERE `Tag`.`id` = 104	1	1	0
SELECT `TagGroup`.`code`, `TagGroup`.`name` FROM `tag_groups` AS `TagGroup` WHERE `TagGroup`.`id` = 7	1	1	0
SELECT `RelatedItem`.`id`, `RelatedItem`.`code`, `RelatedItem`.`name`, `RelatedItem`.`created`, `RelatedItem`.`modified`, `RelatedItem`.`flag` FROM `related_items` AS `RelatedItem` WHERE `code` = 'function' LIMIT 1	1	1	13	maybe slow
SELECT `Content`.`id`, `Content`.`title`, `Content`.`title_en` FROM `contents` AS `Content` WHERE id = (NULL) ORDER BY `id` desc	0	0	0

Message	Memory use
Component intitailization	6.79 MB
Controller action start	6.83 MB
Controller render start	6.90 MB
View render complete	7.92 MB

Message	Time in ms	Graph
Core Processing (Derived)	296.38
Component initialization and startup	15.82
Controller action	62.91
Render Controller Action	82.72
» Rendering View	65.99
» » Rendering APP/views/contents/view.ctp	30.33
» » Rendering APP/views/layouts/default.ctp	19.73
» » » Rendering APP/views/elements/header.ctp	1.52
» » » Rendering APP/views/elements/content_sidebar.ctp	0.40
» » » Rendering APP/views/elements/footer.ctp	0.41

Water-walking Ninjas

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