Robocon 2011: Teams from eight local universities and tertiary institutions show off their engineering and IT skills in a hotly contested robot-building competition (right). Winners earn a slot in an upcoming regional contest in Bangkok. 2.30-5pm, Ocean View Court, The Arcade, Cyberport 3, 100 Cyberport Road. Free. Inquiries: email@example.com 
Legends of Flight Omnimax show traces the evolution of aircraft design. 3.50pm, 7.20pm. Hong Kong Space Museum 10 Salisbury Road; HK$24. Narration available in English for shows on Monday and Thursday.
Volunteering HandsOn Hong Kong, a group dedicated to community-based volunteer work, holds an orientation to give potential helpers a chance to socialise, get to know the organisation and available opportunities to help, from after-school tutoring for ethnic minority students to helping the elderly; 7-8pm; Skylark Lounge, 1/F, Parekh House, 63 Wyndham Street, Central.
Kids Lab How do you clean filthy water? How does a diaper retain so much liquid? Children conduct water-themed experiments at the Science Museum (below) in a programme developed by chemicals giant BASF. Six half-hourly sessions from 2pm. Register up to 15 minutes before each session. 1/F lobby, Hong Kong Science Museum. Inquiries: 2732 3220. Sessions repeat on Saturdays. Saturday
Storytelling Workshops interactive sessions based on award-winning Feng Zikai's children's picture books; 11am, Tai Po Public Library, 8 Heung Sze Wui Street (tel: 2651 4334); 2pm Aberdeen Public Library, 203, Aberdeen Main Road (tel: 2921 1055). Part of a summer reading programme organised by Bring Me a Book charity.